diff --git a/apps/vectorcraft/src/main.rs b/apps/vectorcraft/src/main.rs
index 6c7ebe681..b98681c4c 100644
--- a/apps/vectorcraft/src/main.rs
+++ b/apps/vectorcraft/src/main.rs
@@ -875,6 +875,8 @@ fn main() -> std::process::ExitCode {
                 app.session.swatch_libraries.set_user_dir(swatches);
                 let styles = prefs_path().and_then(|p| Some(p.parent()?.join("Graphic Styles").to_string_lossy().to_string()));
                 app.session.style_libraries.set_user_dir(styles);
+                // With the User Defined libraries listed, the persistent library panels reopen.
+                vectorcraft_ui_egui::panels::library_panel::restore(&mut app);
                 // So do the Libraries panel's libraries; runs without preferences (agents' test
                 // runs) keep theirs for the session only, never touching the user's.
                 if prefs_enabled() {
diff --git a/crates/ui-egui/src/dock.rs b/crates/ui-egui/src/dock.rs
index a4152784d..561d67b02 100644
--- a/crates/ui-egui/src/dock.rs
+++ b/crates/ui-egui/src/dock.rs
@@ -305,12 +305,20 @@ pub(crate) fn panel_tabs(
 /// A panel popped out next to the icon column: an icon panel, or one of the tabbed group's panels
 /// while the dock is collapsed. Dragging its title floats it.
 pub fn floating_panel(app: &mut VectorcraftApp, ctx: &egui::Context) {
-    let Some((id, label)) = app.ui.open_panel.as_deref().and_then(|p| crate::state::all_panels().find(|(q, _)| *q == p)) else { return };
+    let open = app.ui.open_panel.as_deref();
+    let Some(id) =
+        open.and_then(|p| crate::state::all_panels().map(|(q, _)| q).find(|q| *q == p).or_else(|| crate::panels::library_panel::intern(p)))
+    else {
+        return;
+    };
     let tab = DockTab::from_id(id);
     // Expanded, the group shows its panels in the dock itself; a floating panel shows in its group.
     if tab.is_some() && !app.ui.dock_collapsed || floating::group_of(&app.ui, id).is_some() {
         return;
     }
+    // A library panel (in a collapsed dock) is titled by its library's name.
+    let label = crate::panels::library_panel::tab_label(app, id)
+        .unwrap_or_else(|| crate::state::all_panels().find(|(q, _)| *q == id).map_or(id, |(_, label)| tl!(label)).to_string());
     let t = Tokens::get(ctx);
     let screen = ctx.content_rect();
     // Pinned by its right edge, 6 points left of the icon column wherever the dock's width (or its
@@ -338,12 +346,10 @@ pub fn floating_panel(app: &mut VectorcraftApp, ctx: &egui::Context) {
             ui.set_width(width);
             let (strip, _) = ui.allocate_exact_size(vec2(width, 26.0), Sense::hover());
             ui.painter().rect_filled(strip, CornerRadius { nw: 4, ne: 4, sw: 0, se: 0 }, t.panel_darker);
-            let title = Rect::from_min_size(
-                strip.min,
-                vec2(ui.painter().layout_no_wrap(tl!(label).to_string(), theme::semibold(12.0), t.text).size().x + 24.0, 26.0),
-            );
+            let title =
+                Rect::from_min_size(strip.min, vec2(ui.painter().layout_no_wrap(label.clone(), theme::semibold(12.0), t.text).size().x + 24.0, 26.0));
             ui.painter().rect_filled(title, CornerRadius { nw: 4, ne: 0, sw: 0, se: 0 }, t.panel);
-            ui.painter().text(title.left_center() + vec2(12.0, 0.0), egui::Align2::LEFT_CENTER, tl!(label), theme::semibold(12.0), t.text);
+            ui.painter().text(title.left_center() + vec2(12.0, 0.0), egui::Align2::LEFT_CENTER, &label, theme::semibold(12.0), t.text);
             let close = Rect::from_center_size(strip.right_center() - vec2(13.0, 0.0), vec2(14.0, 14.0));
             let cr = ui.interact(close, ui.id().with("close-panel"), Sense::click());
             icons::paint(ui, "chevrons-right", close, if cr.hovered() { t.text } else { t.text_dim });
diff --git a/crates/ui-egui/src/floating.rs b/crates/ui-egui/src/floating.rs
index cd5ec9f6d..a302536c5 100644
--- a/crates/ui-egui/src/floating.rs
+++ b/crates/ui-egui/src/floating.rs
@@ -122,9 +122,15 @@ pub(crate) fn group_rect_id(first: &str) -> Id {
     Id::new(("floating-group-rect", first))
 }
 
-/// Panel `id` (`window.panel`) as a static string and its English label, if it is a panel.
+/// Panel `id` (`window.panel`) as a static string and its English label, if it is a panel (a
+/// library panel's label is its id: [`label`] gives its library's name).
 fn panel(id: &str) -> Option<(&'static str, &'static str)> {
-    all_panels().find(|(p, _)| *p == id)
+    all_panels().find(|(p, _)| *p == id).or_else(|| crate::panels::library_panel::intern(id).map(|p| (p, p)))
+}
+
+/// Panel `id`'s tab label: its English label, or a library panel's library name.
+fn label(app: &VectorcraftApp, id: &str) -> String {
+    crate::panels::library_panel::tab_label(app, id).unwrap_or_else(|| panel(id).map_or(id, |(_, label)| label).to_string())
 }
 
 /// The floating group holding panel `id`.
@@ -816,10 +822,7 @@ fn show_set(app: &mut VectorcraftApp, ctx: &egui::Context, set: &[usize], action
                     let tabs_width: f32 = g
                         .ids
                         .iter()
-                        .map(|id| {
-                            let label = panel(id).map_or(*id, |(_, label)| label);
-                            ui.painter().layout_no_wrap(tl!(label).to_string(), theme::semibold(12.0), t.text).size().x + 24.0
-                        })
+                        .map(|id| ui.painter().layout_no_wrap(tl!(&label(app, id)).to_string(), theme::semibold(12.0), t.text).size().x + 24.0)
                         .sum();
                     g.ids.iter().map(|id| dock::panel_width(id)).fold(tabs_width + 32.0, f32::max)
                 })
@@ -882,7 +885,8 @@ fn draw_groups(
         let lone = g.ids.len() == 1;
         let menu = Rect::from_center_size(strip.right_center() - vec2(14.0, 0.0), vec2(16.0, 16.0));
         let tab_area = Rect::from_min_max(strip.min, pos2((menu.left() - 4.0).max(strip.left()), strip.bottom()));
-        let names: Vec<_> = g.ids.iter().map(|&id| (id, panel(id).map_or(id, |(_, label)| label))).collect();
+        let labels: Vec<String> = g.ids.iter().map(|id| label(app, id)).collect();
+        let names: Vec<_> = g.ids.iter().zip(&labels).map(|(&id, label)| (id, label.as_str())).collect();
         let selected = g.ids.iter().position(|&id| id == g.active).unwrap_or(0);
         let out = dock::panel_tabs(ui, &format!("native-set-tabs-{}", g.gi), tab_area, &names, selected, theme::semibold(12.0), false);
         for (j, resp) in out.responses {
diff --git a/crates/ui-egui/src/i18n/bg.tsv b/crates/ui-egui/src/i18n/bg.tsv
index cdf67d3c2..e71cd258e 100644
--- a/crates/ui-egui/src/i18n/bg.tsv
+++ b/crates/ui-egui/src/i18n/bg.tsv
@@ -5125,3 +5125,5 @@ theme	Appearance	Външен вид
 @msg	name is empty	името е празно
 @msg	no symbol named `{n}`	няма символ с име `{n}`
 	Enable Guides for 9-Slice Scaling	Включване на водачи за 9-slice мащабиране
+	Persistent	Постоянна
+	Library Panel Options	Опции на панела с библиотека
diff --git a/crates/ui-egui/src/i18n/cs.tsv b/crates/ui-egui/src/i18n/cs.tsv
index bd03381a3..58c5877af 100644
--- a/crates/ui-egui/src/i18n/cs.tsv
+++ b/crates/ui-egui/src/i18n/cs.tsv
@@ -5149,3 +5149,9 @@ mark-style	Japanese	Japonské
 @msg	a linked image can't become a gradient mesh: embed it first	propojený obraz nelze převést na síť přechodu: nejprve jej vložte
 @msg	the image has no usable size or position	obraz nemá použitelnou velikost ani polohu
 @msg	the image's pixels can't be read	pixely obrazu nelze přečíst
+	Persistent	Trvalé
+	Library Panel Options	Možnosti panelu knihovny
+@msg	Persistent libraries not found: {files}	Trvalé knihovny nebyly nalezeny: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` není panel knihovny (viz window.swatchLibrary)
+@msg	library panel `{given}` isn't open	panel knihovny `{given}` není otevřený
+@msg	too many library panels were opened in this session	v této relaci bylo otevřeno příliš mnoho panelů knihoven
diff --git a/crates/ui-egui/src/i18n/da.tsv b/crates/ui-egui/src/i18n/da.tsv
index 16b1b98c4..9cf789ac5 100644
--- a/crates/ui-egui/src/i18n/da.tsv
+++ b/crates/ui-egui/src/i18n/da.tsv
@@ -5149,3 +5149,5 @@ swatch	Bright Violet	Kraftig violet
 	Text Orientation	Tekstretning
 	Thread Text	Sammenkæd tekst
 	Typing	Indtastning
+	Persistent	Vedvarende
+	Library Panel Options	Indstillinger for bibliotekspanel
diff --git a/crates/ui-egui/src/i18n/de.tsv b/crates/ui-egui/src/i18n/de.tsv
index fe5f94a01..3fe4c7acf 100644
--- a/crates/ui-egui/src/i18n/de.tsv
+++ b/crates/ui-egui/src/i18n/de.tsv
@@ -4724,3 +4724,9 @@ effect	Regular	Regelmäßig
 @msg	a linked image can't become a gradient mesh: embed it first	ein verknüpftes Bild kann kein Verlaufsgitter werden: Betten Sie es zuerst ein
 @msg	the image has no usable size or position	das Bild hat keine verwendbare Größe oder Position
 @msg	the image's pixels can't be read	die Pixel des Bildes können nicht gelesen werden
+	Persistent	Dauerhaft
+	Library Panel Options	Optionen für das Bibliotheksbedienfeld
+@msg	Persistent libraries not found: {files}	Dauerhafte Bibliotheken nicht gefunden: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` ist kein Bibliotheksbedienfeld (siehe window.swatchLibrary)
+@msg	library panel `{given}` isn't open	Bibliotheksbedienfeld `{given}` ist nicht geöffnet
+@msg	too many library panels were opened in this session	in dieser Sitzung wurden zu viele Bibliotheksbedienfelder geöffnet
diff --git a/crates/ui-egui/src/i18n/el.tsv b/crates/ui-egui/src/i18n/el.tsv
index 06ce80612..8784f0e01 100644
--- a/crates/ui-egui/src/i18n/el.tsv
+++ b/crates/ui-egui/src/i18n/el.tsv
@@ -5101,3 +5101,9 @@ effect	Points	Σημεία
 @msg	a linked image can't become a gradient mesh: embed it first	μια συνδεδεμένη εικόνα δεν μπορεί να γίνει πλέγμα διαβάθμισης: ενσωματώστε την πρώτα
 @msg	the image has no usable size or position	η εικόνα δεν έχει χρησιμοποιήσιμο μέγεθος ή θέση
 @msg	the image's pixels can't be read	τα εικονοστοιχεία της εικόνας δεν μπορούν να διαβαστούν
+	Persistent	Μόνιμη
+	Library Panel Options	Επιλογές πίνακα βιβλιοθήκης
+@msg	Persistent libraries not found: {files}	Δεν βρέθηκαν μόνιμες βιβλιοθήκες: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	Το `{given}` δεν είναι πίνακας βιβλιοθήκης (δείτε window.swatchLibrary)
+@msg	library panel `{given}` isn't open	ο πίνακας βιβλιοθήκης `{given}` δεν είναι ανοιχτός
+@msg	too many library panels were opened in this session	άνοιξαν πάρα πολλοί πίνακες βιβλιοθηκών σε αυτή τη συνεδρία
diff --git a/crates/ui-egui/src/i18n/es.tsv b/crates/ui-egui/src/i18n/es.tsv
index 73e10270a..45c28febb 100644
--- a/crates/ui-egui/src/i18n/es.tsv
+++ b/crates/ui-egui/src/i18n/es.tsv
@@ -5091,3 +5091,9 @@ mark-style	Japanese	Japonesas
 @msg	a linked image can't become a gradient mesh: embed it first	una imagen enlazada no puede convertirse en una malla de degradado: incrústela primero
 @msg	the image has no usable size or position	la imagen no tiene un tamaño ni una posición utilizables
 @msg	the image's pixels can't be read	no se pueden leer los píxeles de la imagen
+	Persistent	Persistente
+	Library Panel Options	Opciones del panel de biblioteca
+@msg	Persistent libraries not found: {files}	No se encontraron bibliotecas persistentes: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` no es un panel de biblioteca (consulte window.swatchLibrary)
+@msg	library panel `{given}` isn't open	el panel de biblioteca `{given}` no está abierto
+@msg	too many library panels were opened in this session	se abrieron demasiados paneles de biblioteca en esta sesión
diff --git a/crates/ui-egui/src/i18n/fi.tsv b/crates/ui-egui/src/i18n/fi.tsv
index 4fceb5391..81aa0e5aa 100644
--- a/crates/ui-egui/src/i18n/fi.tsv
+++ b/crates/ui-egui/src/i18n/fi.tsv
@@ -5113,3 +5113,9 @@ mark-style	Japanese	Japanilainen
 @msg	a linked image can't become a gradient mesh: embed it first	linkitetystä kuvasta ei voi tehdä liukuväriverkkoa: upota se ensin
 @msg	the image has no usable size or position	kuvalla ei ole käyttökelpoista kokoa tai sijaintia
 @msg	the image's pixels can't be read	kuvan pikseleitä ei voi lukea
+	Persistent	Pysyvä
+	Library Panel Options	Kirjastopaneelin asetukset
+@msg	Persistent libraries not found: {files}	Pysyviä kirjastoja ei löytynyt: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` ei ole kirjastopaneeli (katso window.swatchLibrary)
+@msg	library panel `{given}` isn't open	kirjastopaneeli `{given}` ei ole auki
+@msg	too many library panels were opened in this session	tässä istunnossa on avattu liian monta kirjastopaneelia
diff --git a/crates/ui-egui/src/i18n/fr.tsv b/crates/ui-egui/src/i18n/fr.tsv
index 6448eceea..dd4263fd8 100644
--- a/crates/ui-egui/src/i18n/fr.tsv
+++ b/crates/ui-egui/src/i18n/fr.tsv
@@ -5148,3 +5148,9 @@ theme	Appearance	Apparence
 @msg	a linked image can't become a gradient mesh: embed it first	une image liée ne peut pas devenir un filet de dégradé : incorporez-la d’abord
 @msg	the image has no usable size or position	l’image n’a ni taille ni position utilisables
 @msg	the image's pixels can't be read	impossible de lire les pixels de l’image
+	Persistent	Persistante
+	Library Panel Options	Options du panneau de bibliothèque
+@msg	Persistent libraries not found: {files}	Bibliothèques persistantes introuvables : {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` n’est pas un panneau de bibliothèque (voir window.swatchLibrary)
+@msg	library panel `{given}` isn't open	le panneau de bibliothèque `{given}` n’est pas ouvert
+@msg	too many library panels were opened in this session	trop de panneaux de bibliothèque ont été ouverts dans cette session
diff --git a/crates/ui-egui/src/i18n/hu.tsv b/crates/ui-egui/src/i18n/hu.tsv
index 38ab36981..38c20cab4 100644
--- a/crates/ui-egui/src/i18n/hu.tsv
+++ b/crates/ui-egui/src/i18n/hu.tsv
@@ -5135,3 +5135,9 @@ imageTrace	Outline	Körvonal
 @msg	a linked image can't become a gradient mesh: embed it first	csatolt kép nem alakítható színátmenetes hálóvá: előbb ágyazza be
 @msg	the image has no usable size or position	a képnek nincs használható mérete vagy helyzete
 @msg	the image's pixels can't be read	a kép képpontjai nem olvashatók
+	Persistent	Állandó
+	Library Panel Options	Könyvtárpanel beállításai
+@msg	Persistent libraries not found: {files}	Nem találhatók állandó könyvtárak: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	A(z) `{given}` nem könyvtárpanel (lásd: window.swatchLibrary)
+@msg	library panel `{given}` isn't open	a(z) `{given}` könyvtárpanel nincs megnyitva
+@msg	too many library panels were opened in this session	ebben a munkamenetben túl sok könyvtárpanel nyílt meg
diff --git a/crates/ui-egui/src/i18n/id.tsv b/crates/ui-egui/src/i18n/id.tsv
index f1baabca3..201c96ba7 100644
--- a/crates/ui-egui/src/i18n/id.tsv
+++ b/crates/ui-egui/src/i18n/id.tsv
@@ -5149,3 +5149,5 @@ swatch	Bright Violet	Violet cerah
 	Text Orientation	Orientasi teks
 	Thread Text	Untai teks
 	Typing	Mengetik
+	Persistent	Persisten
+	Library Panel Options	Opsi panel pustaka
diff --git a/crates/ui-egui/src/i18n/it.tsv b/crates/ui-egui/src/i18n/it.tsv
index 8a9619eae..0fe7f7209 100644
--- a/crates/ui-egui/src/i18n/it.tsv
+++ b/crates/ui-egui/src/i18n/it.tsv
@@ -4762,3 +4762,9 @@ lighting	Light	Luce
 @msg	a linked image can't become a gradient mesh: embed it first	un’immagine collegata non può diventare una trama sfumata: incorporala prima
 @msg	the image has no usable size or position	l’immagine non ha dimensioni o posizione utilizzabili
 @msg	the image's pixels can't be read	impossibile leggere i pixel dell’immagine
+	Persistent	Persistente
+	Library Panel Options	Opzioni pannello libreria
+@msg	Persistent libraries not found: {files}	Librerie persistenti non trovate: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` non è un pannello libreria (vedi window.swatchLibrary)
+@msg	library panel `{given}` isn't open	il pannello libreria `{given}` non è aperto
+@msg	too many library panels were opened in this session	in questa sessione sono stati aperti troppi pannelli libreria
diff --git a/crates/ui-egui/src/i18n/ja.tsv b/crates/ui-egui/src/i18n/ja.tsv
index d1e893b4f..962caa0a0 100644
--- a/crates/ui-egui/src/i18n/ja.tsv
+++ b/crates/ui-egui/src/i18n/ja.tsv
@@ -4803,3 +4803,9 @@ lighting	Light	ライト
 @msg	a linked image can't become a gradient mesh: embed it first	リンクされた画像はグラデーションメッシュにできません: 先に埋め込んでください
 @msg	the image has no usable size or position	画像に使用できるサイズまたは位置がありません
 @msg	the image's pixels can't be read	画像のピクセルを読み取れません
+	Persistent	永続
+	Library Panel Options	ライブラリパネルオプション
+@msg	Persistent libraries not found: {files}	永続ライブラリが見つかりません: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` はライブラリパネルではありません (window.swatchLibrary を参照)
+@msg	library panel `{given}` isn't open	ライブラリパネル `{given}` は開いていません
+@msg	too many library panels were opened in this session	このセッションで開いたライブラリパネルが多すぎます
diff --git a/crates/ui-egui/src/i18n/ko.tsv b/crates/ui-egui/src/i18n/ko.tsv
index eb4609c32..4becd3292 100644
--- a/crates/ui-egui/src/i18n/ko.tsv
+++ b/crates/ui-egui/src/i18n/ko.tsv
@@ -4726,3 +4726,9 @@ lighting	Light	광원
 @msg	a linked image can't become a gradient mesh: embed it first	연결된 이미지는 그라디언트 메시로 만들 수 없습니다: 먼저 포함하십시오
 @msg	the image has no usable size or position	이미지에 사용할 수 있는 크기나 위치가 없습니다
 @msg	the image's pixels can't be read	이미지의 픽셀을 읽을 수 없습니다
+	Persistent	지속
+	Library Panel Options	라이브러리 패널 옵션
+@msg	Persistent libraries not found: {files}	지속 라이브러리를 찾을 수 없습니다: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}`은(는) 라이브러리 패널이 아닙니다(window.swatchLibrary 참조)
+@msg	library panel `{given}` isn't open	라이브러리 패널 `{given}`이(가) 열려 있지 않습니다
+@msg	too many library panels were opened in this session	이 세션에서 라이브러리 패널을 너무 많이 열었습니다
diff --git a/crates/ui-egui/src/i18n/nl.tsv b/crates/ui-egui/src/i18n/nl.tsv
index 73d78bfdf..fca56ff67 100644
--- a/crates/ui-egui/src/i18n/nl.tsv
+++ b/crates/ui-egui/src/i18n/nl.tsv
@@ -5149,3 +5149,5 @@ swatch	Bright Violet	Felviolet
 	Text Orientation	Tekstrichting
 	Thread Text	Tekst koppelen
 	Typing	Typen
+	Persistent	Permanent
+	Library Panel Options	Opties voor bibliotheekpaneel
diff --git a/crates/ui-egui/src/i18n/pl.tsv b/crates/ui-egui/src/i18n/pl.tsv
index 08192d321..00e128a37 100644
--- a/crates/ui-egui/src/i18n/pl.tsv
+++ b/crates/ui-egui/src/i18n/pl.tsv
@@ -5001,3 +5001,9 @@ mark-style	Japanese	Japońskie
 @msg	a linked image can't become a gradient mesh: embed it first	połączony obraz nie może stać się siatką gradientu: najpierw go osadź
 @msg	the image has no usable size or position	obraz nie ma użytecznego rozmiaru ani położenia
 @msg	the image's pixels can't be read	nie można odczytać pikseli obrazu
+	Persistent	Trwały
+	Library Panel Options	Opcje panelu biblioteki
+@msg	Persistent libraries not found: {files}	Nie znaleziono trwałych bibliotek: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` nie jest panelem biblioteki (zobacz window.swatchLibrary)
+@msg	library panel `{given}` isn't open	panel biblioteki `{given}` nie jest otwarty
+@msg	too many library panels were opened in this session	w tej sesji otwarto zbyt wiele paneli bibliotek
diff --git a/crates/ui-egui/src/i18n/pt-br.tsv b/crates/ui-egui/src/i18n/pt-br.tsv
index 75369c2c9..42db059fb 100644
--- a/crates/ui-egui/src/i18n/pt-br.tsv
+++ b/crates/ui-egui/src/i18n/pt-br.tsv
@@ -5066,3 +5066,9 @@ mark-style	Japanese	Japonesas
 @msg	a linked image can't become a gradient mesh: embed it first	uma imagem vinculada não pode virar uma malha de degradê: incorpore-a primeiro
 @msg	the image has no usable size or position	a imagem não tem tamanho nem posição utilizáveis
 @msg	the image's pixels can't be read	não é possível ler os pixels da imagem
+	Persistent	Persistente
+	Library Panel Options	Opções do Painel de Biblioteca
+@msg	Persistent libraries not found: {files}	Bibliotecas persistentes não encontradas: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` não é um painel de biblioteca (consulte window.swatchLibrary)
+@msg	library panel `{given}` isn't open	o painel de biblioteca `{given}` não está aberto
+@msg	too many library panels were opened in this session	foram abertos painéis de biblioteca demais nesta sessão
diff --git a/crates/ui-egui/src/i18n/ru.tsv b/crates/ui-egui/src/i18n/ru.tsv
index aefc19aee..f3172f779 100644
--- a/crates/ui-egui/src/i18n/ru.tsv
+++ b/crates/ui-egui/src/i18n/ru.tsv
@@ -4758,3 +4758,9 @@ lighting	Light	Свет
 @msg	a linked image can't become a gradient mesh: embed it first	связанное изображение нельзя превратить в сетчатый градиент: сначала встройте его
 @msg	the image has no usable size or position	у изображения нет пригодного размера или положения
 @msg	the image's pixels can't be read	не удаётся прочитать пиксели изображения
+	Persistent	Постоянная
+	Library Panel Options	Параметры панели библиотеки
+@msg	Persistent libraries not found: {files}	Постоянные библиотеки не найдены: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` — не панель библиотеки (см. window.swatchLibrary)
+@msg	library panel `{given}` isn't open	панель библиотеки `{given}` не открыта
+@msg	too many library panels were opened in this session	в этом сеансе открыто слишком много панелей библиотек
diff --git a/crates/ui-egui/src/i18n/sv.tsv b/crates/ui-egui/src/i18n/sv.tsv
index e13931186..9c9249909 100644
--- a/crates/ui-egui/src/i18n/sv.tsv
+++ b/crates/ui-egui/src/i18n/sv.tsv
@@ -5105,3 +5105,9 @@ theme	Appearance	Utseende
 @msg	a linked image can't become a gradient mesh: embed it first	en länkad bild kan inte bli ett övertoningsnät: bädda in den först
 @msg	the image has no usable size or position	bilden har ingen användbar storlek eller position
 @msg	the image's pixels can't be read	bildens pixlar kan inte läsas
+	Persistent	Beständig
+	Library Panel Options	Alternativ för bibliotekspanelen
+@msg	Persistent libraries not found: {files}	Beständiga bibliotek hittades inte: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` är inte en bibliotekspanel (se window.swatchLibrary)
+@msg	library panel `{given}` isn't open	bibliotekspanelen `{given}` är inte öppen
+@msg	too many library panels were opened in this session	för många bibliotekspaneler har öppnats i den här sessionen
diff --git a/crates/ui-egui/src/i18n/uk.tsv b/crates/ui-egui/src/i18n/uk.tsv
index 90faf5e27..d63b0b27e 100644
--- a/crates/ui-egui/src/i18n/uk.tsv
+++ b/crates/ui-egui/src/i18n/uk.tsv
@@ -4742,3 +4742,9 @@ lighting	Light	Світло
 @msg	a linked image can't become a gradient mesh: embed it first	зв’язане зображення не можна перетворити на сітчастий градієнт: спочатку вбудуйте його
 @msg	the image has no usable size or position	зображення не має придатного розміру чи положення
 @msg	the image's pixels can't be read	не вдається прочитати пікселі зображення
+	Persistent	Постійна
+	Library Panel Options	Параметри панелі бібліотеки
+@msg	Persistent libraries not found: {files}	Постійні бібліотеки не знайдено: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` — не панель бібліотеки (див. window.swatchLibrary)
+@msg	library panel `{given}` isn't open	панель бібліотеки `{given}` не відкрита
+@msg	too many library panels were opened in this session	у цьому сеансі відкрито забагато панелей бібліотек
diff --git a/crates/ui-egui/src/i18n/vi.tsv b/crates/ui-egui/src/i18n/vi.tsv
index 703a62194..88dbab7b6 100644
--- a/crates/ui-egui/src/i18n/vi.tsv
+++ b/crates/ui-egui/src/i18n/vi.tsv
@@ -4742,3 +4742,9 @@ theme	Appearance	Giao diện
 @msg	a linked image can't become a gradient mesh: embed it first	không thể biến ảnh liên kết thành lưới chuyển sắc: hãy nhúng ảnh trước
 @msg	the image has no usable size or position	ảnh không có kích thước hoặc vị trí dùng được
 @msg	the image's pixels can't be read	không đọc được các điểm ảnh của ảnh
+	Persistent	Lưu giữ
+	Library Panel Options	Tùy chọn bảng thư viện
+@msg	Persistent libraries not found: {files}	Không tìm thấy thư viện lưu giữ: {files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` không phải là bảng thư viện (xem window.swatchLibrary)
+@msg	library panel `{given}` isn't open	bảng thư viện `{given}` chưa được mở
+@msg	too many library panels were opened in this session	đã mở quá nhiều bảng thư viện trong phiên này
diff --git a/crates/ui-egui/src/i18n/zh-hans.tsv b/crates/ui-egui/src/i18n/zh-hans.tsv
index 71910103e..bfc4ad1d4 100644
--- a/crates/ui-egui/src/i18n/zh-hans.tsv
+++ b/crates/ui-egui/src/i18n/zh-hans.tsv
@@ -4985,3 +4985,9 @@ lighting	Light	光源
 @msg	a linked image can't become a gradient mesh: embed it first	链接的图像无法转换为渐变网格：请先嵌入它
 @msg	the image has no usable size or position	图像没有可用的尺寸或位置
 @msg	the image's pixels can't be read	无法读取图像的像素
+	Persistent	持久
+	Library Panel Options	库面板选项
+@msg	Persistent libraries not found: {files}	找不到持久库：{files}
+@msg	`{given}` isn't a library panel (see window.swatchLibrary)	`{given}` 不是库面板 (请参阅 window.swatchLibrary)
+@msg	library panel `{given}` isn't open	库面板 `{given}` 未打开
+@msg	too many library panels were opened in this session	本次会话中打开的库面板过多
diff --git a/crates/ui-egui/src/i18n/zh-hant.tsv b/crates/ui-egui/src/i18n/zh-hant.tsv
index c339769b0..21a188c4f 100644
--- a/crates/ui-egui/src/i18n/zh-hant.tsv
+++ b/crates/ui-egui/src/i18n/zh-hant.tsv
@@ -4058,3 +4058,5 @@ lighting	Light	光源
 @msg	name is empty	名稱為空
 @msg	no symbol named `{n}`	沒有名為 `{n}` 的符號
 	Enable Guides for 9-Slice Scaling	啟用 9-slice 縮放參考線
+	Persistent	持久
+	Library Panel Options	資料庫面板選項
diff --git a/crates/ui-egui/src/lib.rs b/crates/ui-egui/src/lib.rs
index 65f4c4397..1ea705cbf 100644
--- a/crates/ui-egui/src/lib.rs
+++ b/crates/ui-egui/src/lib.rs
@@ -1387,6 +1387,7 @@ impl VectorcraftApp {
         if self.ui.toolbar && self.ui.screen_mode < 3 {
             toolbar::show(self, ui);
         }
+        panels::library_panel::tidy(self);
         if self.ui.dock && self.ui.screen_mode < 3 {
             dock::show(self, ui);
         }
@@ -1398,7 +1399,6 @@ impl VectorcraftApp {
         });
         dock::floating_panel(self, &ctx);
         floating::show(self, &ctx);
-        panels::library_panel::show_window(self, &ctx);
         dialogs::show(self, &ctx);
         palette::show(self, &ctx);
         if self.custom_titlebar {
diff --git a/crates/ui-egui/src/menus.rs b/crates/ui-egui/src/menus.rs
index 788e58248..690cbc883 100644
--- a/crates/ui-egui/src/menus.rs
+++ b/crates/ui-egui/src/menus.rs
@@ -495,13 +495,19 @@ pub const UI_COMMANDS: &[(&str, &str, &str, &str)] = &[
         "window.swatchLibrary",
         "Swatch Library",
         "",
-        "{library: id or name (see swatch.library.list) | null (close)} open the read-only library panel on a swatch library (UI state `library_panel`); clicking a swatch there runs swatch.library.add with apply → {open, name, count}",
+        "{library: id or name (see swatch.library.list) | null (close every swatch library panel)} open the swatch library in a read-only panel of its own, floating (panel id `library:swatches:<id>`, which window.panel.* moves, docks and closes), or bring its panel forward when it is open; clicking a swatch there runs swatch.library.add with apply. ui.libraryPanel sets its view, find field and Persistent (ui.inspect: ui.library_panels) → {open: id, panel, name, count}",
     ),
     (
         "window.swatchLibrary.other",
         "Other Library…",
         "",
-        "{path?} (default: pick a file) load a .vcswatches, .gpl, .ase or .acb (color book) library, or another document's swatches (engine: swatch.library.load), and open it in the library panel",
+        "{path?} (default: pick a file) load a .vcswatches, .gpl, .ase or .acb (color book) library, or another document's swatches (engine: swatch.library.load), and open it in its library panel",
+    ),
+    (
+        "ui.libraryPanel",
+        "Library Panel Options",
+        "",
+        "{panel: a library panel's id (`library:swatches:pastels`, as window.swatchLibrary answers), library?: id or name of another library of its kind to show in the panel (Previous / Next Library; one open in a panel of its own is brought forward instead), view?: smallThumb|mediumThumb|largeThumb|smallList|largeList, showFind?: bool, persistent?: bool (reopen the panel when the app starts)} set an open library panel, or a closed persistent one's view, Show Find Field and Persistent; kept with the preferences (ui.inspect: ui.library_panels) → {panel, kind, library, view, showFind, persistent, open}",
     ),
     (
         "ui.saveSwatchLibrary",
@@ -589,13 +595,13 @@ pub const UI_COMMANDS: &[(&str, &str, &str, &str)] = &[
         "window.graphicStyleLibrary",
         "Graphic Style Library",
         "",
-        "{library: id or name (see graphicStyle.libraries) | null (close)} open the read-only library panel on a graphic style library (UI state `library_panel`, kind graphicStyles); clicking a style there runs graphicStyle.addFromLibrary with apply (Alt: add) → {open, name, count}",
+        "{library: id or name (see graphicStyle.libraries) | null (close every graphic style library panel)} open the graphic style library in a read-only panel of its own, floating (panel id `library:graphicStyles:<id>`), or bring its panel forward when it is open; clicking a style there runs graphicStyle.addFromLibrary with apply (Alt: add). ui.libraryPanel sets its view, find field and Persistent → {open: id, panel, name, count}",
     ),
     (
         "window.graphicStyleLibrary.other",
         "Other Library…",
         "",
-        "{path?} (default: pick a file) load a .vcstyles library, or another document's graphic styles (engine: graphicStyle.loadLibrary), and open it in the library panel",
+        "{path?} (default: pick a file) load a .vcstyles library, or another document's graphic styles (engine: graphicStyle.loadLibrary), and open it in its library panel",
     ),
     (
         "ui.saveGraphicStyleLibrary",
@@ -992,10 +998,14 @@ pub const UI_COMMANDS: &[(&str, &str, &str, &str)] = &[
 ];
 
 /// Canonical panel id for `window.panel`: a dock tab's or an icon panel's id or display label,
-/// matched case-insensitively (`"Layers"`, `"swatches"`, `"Color Guide"`).
+/// matched case-insensitively (`"Layers"`, `"swatches"`, `"Color Guide"`), or a library panel's id
+/// as it is (`library:swatches:pastels`).
 pub(crate) fn normalize_panel(input: &str) -> Option<&'static str> {
     let name = input.trim();
-    crate::state::all_panels().find(|(id, label)| name.eq_ignore_ascii_case(id) || name.eq_ignore_ascii_case(label)).map(|(id, _)| id)
+    crate::state::all_panels()
+        .find(|(id, label)| name.eq_ignore_ascii_case(id) || name.eq_ignore_ascii_case(label))
+        .map(|(id, _)| id)
+        .or_else(|| crate::panels::library_panel::intern(input))
 }
 
 /// An optional `{key?: bool}` param: none when it is omitted or null (the commands then toggle).
@@ -1405,6 +1415,8 @@ pub fn run_ui_command(app: &mut VectorcraftApp, id: &str, p: &Value) -> Option<R
                     app.ui.dock_tab = tab;
                     Ok(Value::Null)
                 }
+                // A library panel isn't in the icon column: it floats.
+                (Some(p), None) if crate::panels::library_panel::parse(p).is_some() => crate::panels::library_panel::float(app, p),
                 (Some(p), None) => {
                     app.ui.open_panel = if app.ui.open_panel.as_deref() == Some(p) { None } else { Some(p.to_string()) };
                     app.ui.dock = true;
@@ -1538,6 +1550,7 @@ pub fn run_ui_command(app: &mut VectorcraftApp, id: &str, p: &Value) -> Option<R
         }
         "ui.flattenerPreview" => crate::panels::flattener_preview::command(app, p),
         "window.graphicStyleLibrary" => crate::panels::graphic_styles::open_library(app, p),
+        "ui.libraryPanel" => crate::panels::library_panel::command(app, p),
         "window.graphicStyleLibrary.other" => crate::panels::graphic_styles::other_library(app, s("path")),
         "ui.saveGraphicStyleLibrary" => {
             let names = p.get("names").and_then(Value::as_array).map(|a| a.iter().filter_map(Value::as_str).map(str::to_string).collect());
diff --git a/crates/ui-egui/src/panel_docking.rs b/crates/ui-egui/src/panel_docking.rs
index 7e1df99c4..a90c4bf5c 100644
--- a/crates/ui-egui/src/panel_docking.rs
+++ b/crates/ui-egui/src/panel_docking.rs
@@ -625,6 +625,13 @@ pub(crate) fn show(app: &mut VectorcraftApp, ui: &mut egui::Ui) -> bool {
     display
         .floating
         .retain(|group| !app.ui.floating_panels.iter().any(|native| decorated(native) && native.panels.iter().any(|id| group.panels.contains(id))));
+    // Library panels are titled by their libraries' names.
+    let library_labels: Vec<(String, String)> = layout
+        .panels()
+        .into_iter()
+        .filter_map(|panel| crate::panels::library_panel::tab_label(app, panel).map(|label| (panel.clone(), label)))
+        .collect();
+    let library_label = |panel: &str| library_labels.iter().find(|(p, _)| p == panel).map(|(_, label)| label.clone());
     // Floating groups lie on the canvas, not on the dock's card: reserve a fill under each one
     // before the dock draws it, sized once it is placed, so the canvas doesn't show through (#2421).
     let fills: Vec<_> = display
@@ -646,8 +653,16 @@ pub(crate) fn show(app: &mut VectorcraftApp, ui: &mut egui::Ui) -> bool {
                 let info = crate::state::DockTab::from_id(panel)
                     .map(|tab| tab.info())
                     .or_else(|| crate::state::ICON_PANELS.iter().find(|entry| entry.0 == panel).copied());
-                if let Some((_, label, icon)) = info
-                    && crate::widgets::icon_button(ui, icon, tl!(label), app.ui.open_panel.as_ref() == Some(panel), 30.0).clicked()
+                let label = info.map(|(_, label, _)| tl!(label).to_string()).or_else(|| library_label(panel));
+                if let Some(label) = label
+                    && crate::widgets::icon_button(
+                        ui,
+                        info.map_or("library", |(_, _, icon)| icon),
+                        &label,
+                        app.ui.open_panel.as_ref() == Some(panel),
+                        30.0,
+                    )
+                    .clicked()
                 {
                     app.ui.open_panel = if app.ui.open_panel.as_ref() == Some(panel) { None } else { Some(panel.clone()) };
                 }
@@ -675,7 +690,13 @@ pub(crate) fn show(app: &mut VectorcraftApp, ui: &mut egui::Ui) -> bool {
             ui,
             &display,
             &style,
-            |id| crate::state::all_panels().find(|p| p.0 == id).map(|p| tl!(p.1).to_string()).unwrap_or_else(|| id.clone()),
+            |id| {
+                crate::state::all_panels()
+                    .find(|p| p.0 == id)
+                    .map(|p| tl!(p.1).to_string())
+                    .or_else(|| library_label(id))
+                    .unwrap_or_else(|| id.clone())
+            },
             |_| craft_ui::docking::Permissions::default(),
             |_| craft_ui::docking::PanelLimits { min: egui::vec2(220.0, 80.0), ..Default::default() },
             &mut content,
diff --git a/crates/ui-egui/src/panel_docking_tests.rs b/crates/ui-egui/src/panel_docking_tests.rs
index f0a556d51..01b6ca9ba 100644
--- a/crates/ui-egui/src/panel_docking_tests.rs
+++ b/crates/ui-egui/src/panel_docking_tests.rs
@@ -640,3 +640,35 @@ fn floating_group_paints_an_opaque_background() {
     assert!(opaque_at(pos2(690.0, 210.0)), "tab strip is transparent");
     assert!(opaque_at(pos2(690.0, 610.0)), "body is transparent");
 }
+
+/// Library panels (#2603) float in the shared layout titled by their libraries' names, and their
+/// menu's Persistent item keeps them for the next launch.
+#[test]
+fn library_panels_float_with_their_names_and_a_persistent_menu_item() {
+    let mut app = app();
+    app.run("file.new", json!({})).unwrap();
+    for (library, x) in [("pastels", 40), ("brights", 420)] {
+        let panel = format!("library:swatches:{library}");
+        app.run("window.swatchLibrary", json!({"library": library})).unwrap();
+        app.run("window.panel.float", json!({"panel": panel, "x": x, "y": 100})).unwrap();
+    }
+    let mut h = harness(app, vec2(1280.0, 900.0));
+    for name in ["Pastels", "Brights"] {
+        assert!(h.query_all_by_label(name).next().is_some(), "the {name} tab");
+    }
+    let click = |h: &mut Harness<'static, VectorcraftApp>, at: Pos2| {
+        h.hover_at(at);
+        h.run_steps(1);
+        for pressed in [true, false] {
+            h.event(Event::PointerButton { pos: at, button: PointerButton::Primary, pressed, modifiers: Modifiers::NONE });
+            h.run_steps(1);
+        }
+        h.run_steps(2);
+    };
+    let menu = h.query_all_by_label("Panel menu").find(|node| node.rect().center().x < 400.0).expect("the Pastels panel's menu").rect().center();
+    click(&mut h, menu);
+    let item = h.query_all_by_label("   Persistent").next().expect("Persistent is in the panel menu").rect().center();
+    click(&mut h, item);
+    let persistent: Vec<&str> = h.state().ui.library_panels.iter().filter(|p| p.persistent).map(|p| p.id.as_str()).collect();
+    assert_eq!(persistent, ["pastels"]);
+}
diff --git a/crates/ui-egui/src/panels/color_guide.rs b/crates/ui-egui/src/panels/color_guide.rs
index 8de5ff1eb..459d5a3ab 100644
--- a/crates/ui-egui/src/panels/color_guide.rs
+++ b/crates/ui-egui/src/panels/color_guide.rs
@@ -103,7 +103,7 @@ fn limit_menu(app: &mut VectorcraftApp, ui: &mut Ui) {
         }
     }
     ui.separator();
-    chosen = library_panel::library_items(ui, &colour_libraries(app), Some(&cur)).or(chosen);
+    chosen = library_panel::library_items(ui, &colour_libraries(app), &|id| id == cur).or(chosen);
     if let Some(key) = chosen {
         set_limit(app, &json!({ "library": key })).ok();
         clear_selection(ui.ctx());
diff --git a/crates/ui-egui/src/panels/graphic_styles.rs b/crates/ui-egui/src/panels/graphic_styles.rs
index 6e488ca65..d20e54a22 100644
--- a/crates/ui-egui/src/panels/graphic_styles.rs
+++ b/crates/ui-egui/src/panels/graphic_styles.rs
@@ -6,7 +6,7 @@
 //! to the art it is dropped on (`canvas::panel_drop`); art dragged off the canvas or the Appearance
 //! panel's thumbnail dropped on the panel becomes a new style. Holding the right button on a style
 //! shows it large, on the selected object when there is one. The Control bar's Style picker lists
-//! the same tiles ([`picker`]). Graphic style libraries open in the library panel
+//! the same tiles ([`picker`]). Graphic style libraries open in library panels
 //! ([`GraphicStyleLibraries`]).
 
 use std::cell::RefCell;
@@ -479,7 +479,7 @@ pub fn show(app: &mut VectorcraftApp, ui: &mut Ui) {
     let has_sel = selection_len(app) > 0;
     let linked = app.session.selection_graphic_style().is_some();
     widgets::bottom_bar(ui, |ui| {
-        let open = app.ui.library_panel.as_ref().is_some_and(|o| o.kind == GraphicStyleLibraries::KIND);
+        let open = library_panel::any_open::<GraphicStyleLibraries>(&app.ui);
         let lr = widgets::icon_button(ui, "library", GraphicStyleLibraries::MENU, open, 24.0);
         egui::Popup::menu(&lr).show(|ui| {
             ui.set_min_width(200.0);
@@ -681,13 +681,15 @@ fn describe(g: &GraphicStyle) -> String {
     parts.join(", ")
 }
 
-/// Graphic style libraries in the library panel (engine: `graphicStyle.libraries`,
+/// Graphic style libraries in library panels (engine: `graphicStyle.libraries`,
 /// `graphicStyle.addFromLibrary`…).
 pub(crate) struct GraphicStyleLibraries;
 
 impl LibraryKind for GraphicStyleLibraries {
     const KIND: &'static str = "graphicStyles";
     const OPEN: &'static str = "window.graphicStyleLibrary";
+    const LIST: &'static str = "graphicStyle.libraries";
+    const LOAD: &'static str = "graphicStyle.loadLibrary";
     const MENU: &'static str = "Graphic Style Libraries Menu";
     const ADD: &'static str = "Add to Graphic Styles";
     /// Styles need room to show their effects.
@@ -702,6 +704,12 @@ impl LibraryKind for GraphicStyleLibraries {
     fn get(app: &VectorcraftApp, id: &str) -> Option<(String, Self::Lib)> {
         stylelib::library(&app.session, id).map(|(info, lib)| (info.name, shown_library(lib)))
     }
+    fn find(app: &VectorcraftApp, key: &str) -> Option<(String, String, usize)> {
+        stylelib::library(&app.session, key).map(|(info, lib)| (info.id, info.name, lib.len()))
+    }
+    fn path(app: &VectorcraftApp, id: &str) -> Option<String> {
+        app.session.style_libraries.path(id).map(str::to_string)
+    }
     fn rows<'a>(lib: &'a Self::Lib, query: &str) -> Vec<Row<'a, LibStyle>> {
         let found = |n: &str| query.is_empty() || n.to_lowercase().contains(query);
         lib.iter().filter(|s| found(&s.style().name)).map(|s| Row { name: &s.style().name, item: Some(s) }).collect()
@@ -740,15 +748,13 @@ impl LibraryKind for GraphicStyleLibraries {
     }
 }
 
-/// `window.graphicStyleLibrary {library}`: open a graphic style library in the library panel
-/// (`library` null closes it).
+/// `window.graphicStyleLibrary {library}`: open a graphic style library in its own panel
+/// (`library` null closes every graphic style library panel).
 pub(crate) fn open_library(app: &mut VectorcraftApp, p: &Value) -> Result<Value, String> {
-    library_panel::open_command::<GraphicStyleLibraries>(app, p, "graphicStyle.libraries", |app, key| {
-        stylelib::library(&app.session, key).map(|(info, lib)| (info.id, info.name, lib.len()))
-    })
+    library_panel::open_command::<GraphicStyleLibraries>(app, p)
 }
 
-/// `graphicStyle.loadLibrary` params, then open the library in the panel.
+/// `graphicStyle.loadLibrary` params, then open the library in its panel.
 pub(crate) fn load_library(app: &mut VectorcraftApp, params: Value) -> Result<Value, String> {
     let r = app.run("graphicStyle.loadLibrary", params)?;
     open_library(app, &json!({ "library": r["library"] }))
diff --git a/crates/ui-egui/src/panels/image_trace.rs b/crates/ui-egui/src/panels/image_trace.rs
index ae02d1cbf..345408428 100644
--- a/crates/ui-egui/src/panels/image_trace.rs
+++ b/crates/ui-egui/src/panels/image_trace.rs
@@ -53,7 +53,7 @@ fn library_label(app: &VectorcraftApp, key: &str) -> String {
 fn library_list(app: &VectorcraftApp, ui: &mut Ui, current: &str) -> Option<String> {
     let document = menu_item(ui, swatches::DOCUMENT_SWATCHES, true, current == DOCUMENT_SWATCHES).then(|| DOCUMENT_SWATCHES.to_string());
     ui.separator();
-    library_panel::library_items(ui, &swatches::colour_libraries(app), Some(current)).or(document)
+    library_panel::library_items(ui, &swatches::colour_libraries(app), &|id| id == current).or(document)
 }
 
 /// Panel state: the preset name, the current parameters, the view and the last result's counts.
diff --git a/crates/ui-egui/src/panels/library_panel.rs b/crates/ui-egui/src/panels/library_panel.rs
index 0d0c1f2af..32c30bd04 100644
--- a/crates/ui-egui/src/panels/library_panel.rs
+++ b/crates/ui-egui/src/panels/library_panel.rs
@@ -1,30 +1,62 @@
-//! The library panel: a floating, read-only view of one library (swatch and graphic style
-//! libraries; any kind of library implementing [`LibraryKind`]) with thumbnail and list views, a
-//! find field, the libraries menu and previous / next arrows. A plain click on an item adds it to
-//! the document and applies it; Shift and Cmd/Ctrl-clicks select items (and folders) for Add to ….
+//! Library panels: read-only views of one library each (swatch and graphic style libraries; any
+//! kind of library implementing [`LibraryKind`]) with thumbnail and list views, a find field, the
+//! libraries menu and previous / next arrows. A plain click on an item adds it to the document and
+//! applies it; Shift and Cmd/Ctrl-clicks select items (and folders) for Add to ….
 //!
-//! Which library is open lives in `UiState::library_panel` (`window.swatchLibrary` and
-//! `window.graphicStyleLibrary` open one), so agents can open and read it; the view, find text and
-//! selection are panel state.
+//! As in Illustrator (<https://helpx.adobe.com/illustrator/using/using-creating-swatches.html>,
+//! "Swatch libraries"), each open library is a panel of its own, `library:<kind>:<library id>`
+//! ([`panel_id`]), that floats, tabs, docks and closes as any panel of the shared docking system:
+//! `window.swatchLibrary` and `window.graphicStyleLibrary` open one, or bring it forward when it is
+//! open. `UiState::library_panels` keeps each one's view, Show Find Field and Persistent
+//! (`ui.libraryPanel`); a persistent panel reopens when the app starts ([`restore`]). The find text
+//! and the selection are panel state.
 
-use egui::{CornerRadius, Rect, Sense, Ui, vec2};
+use std::sync::{Mutex, PoisonError};
+
+use egui::{Rect, Sense, Ui};
 use serde::{Deserialize, Serialize};
 use serde_json::{Value, json};
 use vectorcraft_engine::cmd::swatchlib::LibraryInfo;
 
 use super::swatches::{View, click_selection, folder_tile, list_row, list_row_name, tile_grid};
 use super::{pstate, set_pstate};
-use crate::theme::{self, Tokens};
+use crate::VectorcraftApp;
+use crate::state::UiState;
 use crate::widgets::{self, menu_item};
-use crate::{VectorcraftApp, icons};
 
-/// The library open in the library panel.
+/// What every library panel's id starts with.
+pub const PREFIX: &str = "library:";
+
+/// The most library panels one session opens: their ids are interned ([`intern`]).
+const MAX_PANELS: usize = 256;
+
+/// A library panel's settings: one per library opened this session, and the persistent ones
+/// (also once closed), most recently opened or brought forward last.
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
-pub struct OpenLibrary {
+pub struct LibraryPanel {
     /// The kind of library ([`LibraryKind::KIND`], e.g. "swatches").
     pub kind: String,
     /// The library's id.
     pub id: String,
+    /// The file a loaded library was read from, which [`restore`] reads it from again.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub path: Option<String>,
+    /// The view picked from the panel menu (none: the kind's, [`LibraryKind::VIEW`]).
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub view: Option<View>,
+    /// Show Find Field is off.
+    #[serde(default)]
+    pub hide_find: bool,
+    /// Persistent: the panel reopens when the app starts.
+    #[serde(default)]
+    pub persistent: bool,
+}
+
+impl LibraryPanel {
+    /// The panel's id.
+    pub fn panel(&self) -> String {
+        panel_id(&self.kind, &self.id)
+    }
 }
 
 /// A library as the libraries menu lists it.
@@ -41,17 +73,21 @@ pub(crate) struct Row<'a, I> {
     pub item: Option<&'a I>,
 }
 
-/// One kind of library the panel shows.
+/// One kind of library the panels show.
 pub(crate) trait LibraryKind {
-    /// `OpenLibrary::kind`, and the prefix of the panel's state keys.
+    /// `LibraryPanel::kind`, and the middle part of its panels' ids.
     const KIND: &'static str;
-    /// The UI command that opens a library in the panel (`{library: id}`).
+    /// The UI command that opens a library's panel (`{library: id}`).
     const OPEN: &'static str;
+    /// The engine command listing the libraries, for error messages.
+    const LIST: &'static str;
+    /// The engine command loading a library from a file (`{path}` → `{library}`).
+    const LOAD: &'static str;
     /// The libraries menu's tooltip ("Swatch Libraries Menu").
     const MENU: &'static str;
     /// What adding the selection is called ("Add to Swatches").
     const ADD: &'static str;
-    /// The view the panel shows until another is picked.
+    /// The view a panel shows until another is picked.
     const VIEW: View = View::MediumThumb;
     /// A library's contents, cheap to clone.
     type Lib;
@@ -60,6 +96,10 @@ pub(crate) trait LibraryKind {
     fn list(app: &VectorcraftApp) -> Vec<LibraryRef>;
     /// Library `id`: its name and contents.
     fn get(app: &VectorcraftApp, id: &str) -> Option<(String, Self::Lib)>;
+    /// Library `key` (an id or a name).
+    fn find(app: &VectorcraftApp, key: &str) -> Found;
+    /// The file library `id` was read from, if any.
+    fn path(app: &VectorcraftApp, id: &str) -> Option<String>;
     /// The rows matching the find field's `query` (lower case; empty: all).
     fn rows<'a>(lib: &'a Self::Lib, query: &str) -> Vec<Row<'a, Self::Item>>;
     /// An item's thumbnail in `r`.
@@ -78,31 +118,236 @@ pub(crate) trait LibraryKind {
     fn menu_tail(_app: &mut VectorcraftApp, _ui: &mut Ui) {}
 }
 
-/// The state key `key` of `K`'s panel.
-fn key<K: LibraryKind>(key: &str) -> String {
-    format!("{}-library-{key}", K::KIND)
+/// A library looked up by its id or name: its id, name and item count.
+pub(crate) type Found = Option<(String, String, usize)>;
+
+/// What code that knows a library panel by its id alone needs of its kind.
+#[derive(Clone, Copy)]
+pub(crate) struct Kind {
+    pub kind: &'static str,
+    list: &'static str,
+    load: &'static str,
+    view: View,
+    name: fn(&VectorcraftApp, &str) -> Option<String>,
+    find: fn(&VectorcraftApp, &str) -> Found,
+    path: fn(&VectorcraftApp, &str) -> Option<String>,
+    body: fn(&mut VectorcraftApp, &mut Ui, &str),
+    menu: fn(&mut VectorcraftApp, &mut Ui, &str),
 }
 
-/// The view of `K`'s panel.
-fn view<K: LibraryKind>(ctx: &egui::Context) -> View {
-    pstate::<Option<View>>(ctx, &key::<K>("view")).unwrap_or(K::VIEW)
-}
-
-/// The interaction id of the tile or row of `name`.
-pub(crate) fn tile_id<K: LibraryKind>(name: &str) -> egui::Id {
-    egui::Id::new(("library-tile", K::KIND, name))
-}
-
-/// Draw the open library panel, if any.
-pub fn show_window(app: &mut VectorcraftApp, ctx: &egui::Context) {
-    let Some(open) = app.ui.library_panel.clone() else { return };
-    match open.kind.as_str() {
-        super::swatches::SwatchLibraries::KIND => window::<super::swatches::SwatchLibraries>(app, ctx, &open.id),
-        super::graphic_styles::GraphicStyleLibraries::KIND => window::<super::graphic_styles::GraphicStyleLibraries>(app, ctx, &open.id),
-        _ => app.ui.library_panel = None,
+fn kind_of<K: LibraryKind>() -> Kind {
+    Kind {
+        kind: K::KIND,
+        list: K::LIST,
+        load: K::LOAD,
+        view: K::VIEW,
+        name: |app, id| K::get(app, id).map(|(name, _)| name),
+        find: K::find,
+        path: K::path,
+        body: body::<K>,
+        menu: panel_menu::<K>,
     }
 }
 
+/// The kind of library `kind` names.
+fn kind(kind: &str) -> Option<Kind> {
+    [kind_of::<super::swatches::SwatchLibraries>(), kind_of::<super::graphic_styles::GraphicStyleLibraries>()].into_iter().find(|k| k.kind == kind)
+}
+
+/// The id of the panel of library `id` of `kind` (`library:swatches:pastels`).
+pub fn panel_id(kind: &str, id: &str) -> String {
+    format!("{PREFIX}{kind}:{id}")
+}
+
+/// The kind and library id of library panel `panel`.
+pub(crate) fn parse(panel: &str) -> Option<(Kind, &str)> {
+    let (k, id) = panel.strip_prefix(PREFIX)?.split_once(':')?;
+    if id.is_empty() || panel.len() > 1024 {
+        return None;
+    }
+    Some((kind(k)?, id))
+}
+
+/// Library panel `panel` as the `&'static str` the docking code keeps panel ids as
+/// ([`crate::menus::normalize_panel`]); `None` when it isn't a library panel's id.
+/// shortcut: each id is leaked once, at most `MAX_PANELS` of them (more libraries than one session
+/// opens); make the docking code keep owned ids if that ever binds.
+pub(crate) fn intern(panel: &str) -> Option<&'static str> {
+    parse(panel)?;
+    static IDS: Mutex<Vec<&'static str>> = Mutex::new(Vec::new());
+    let mut ids = IDS.lock().unwrap_or_else(PoisonError::into_inner);
+    if let Some(id) = ids.iter().find(|id| **id == panel) {
+        return Some(id);
+    }
+    if ids.len() >= MAX_PANELS {
+        return None;
+    }
+    let id: &'static str = Box::leak(panel.into());
+    ids.push(id);
+    Some(id)
+}
+
+/// [`intern`], failing as a command does.
+fn registered(panel: &str) -> Result<&'static str, String> {
+    intern(panel).ok_or_else(|| "too many library panels were opened in this session".into())
+}
+
+/// Is panel `panel` open (in the dock or floating)?
+pub(crate) fn is_open(ui: &UiState, panel: &str) -> bool {
+    ui.docking.as_ref().is_some_and(|l| l.panels().iter().any(|p| p.as_str() == panel)) || crate::floating::group_of(ui, panel).is_some()
+}
+
+/// The open library panels.
+fn open_panels(ui: &UiState) -> Vec<String> {
+    let mut out: Vec<String> = vec![];
+    let docked = ui.docking.iter().flat_map(|l| l.panels());
+    for p in docked.chain(ui.floating_panels.iter().flat_map(|g| &g.panels)) {
+        if p.starts_with(PREFIX) && !out.contains(p) {
+            out.push(p.clone());
+        }
+    }
+    out
+}
+
+/// Is a library panel of kind `K` open?
+pub(crate) fn any_open<K: LibraryKind>(ui: &UiState) -> bool {
+    open_panels(ui).iter().any(|p| parse(p).is_some_and(|(k, _)| k.kind == K::KIND))
+}
+
+/// The library panel opened or brought forward last that is open.
+#[cfg(test)]
+pub(crate) fn last_open(ui: &UiState) -> Option<&LibraryPanel> {
+    ui.library_panels.iter().rev().find(|p| is_open(ui, &p.panel()))
+}
+
+fn settings<'a>(ui: &'a UiState, kind: &str, id: &str) -> Option<&'a LibraryPanel> {
+    ui.library_panels.iter().find(|p| p.kind == kind && p.id == id)
+}
+
+/// The settings of library `id`'s panel, made when it has none.
+fn settings_mut<'a>(app: &'a mut VectorcraftApp, k: Kind, id: &str) -> Option<&'a mut LibraryPanel> {
+    if settings(&app.ui, k.kind, id).is_none() {
+        let path = if id.starts_with("loaded/") { (k.path)(app, id) } else { None };
+        app.ui.library_panels.push(LibraryPanel { kind: k.kind.into(), id: id.into(), path, view: None, hide_find: false, persistent: false });
+    }
+    app.ui.library_panels.iter_mut().find(|p| p.kind == k.kind && p.id == id)
+}
+
+/// Library panel `panel`'s tab label: its library's name (a built-in one's in the UI language).
+pub(crate) fn tab_label(app: &VectorcraftApp, panel: &str) -> Option<String> {
+    let (k, id) = parse(panel)?;
+    (k.name)(app, id).map(|name| library_name(id, &name).to_string())
+}
+
+/// Library panel `panel`'s contents (the dock or its floating group draws its tab and menu button).
+pub(crate) fn show(app: &mut VectorcraftApp, ui: &mut Ui, panel: &str) {
+    if let Some((k, id)) = parse(panel) {
+        (k.body)(app, ui, id);
+    }
+}
+
+/// Library panel `panel`'s (≡) menu items.
+pub(crate) fn menu(app: &mut VectorcraftApp, ui: &mut Ui, panel: &str) {
+    if let Some((k, id)) = parse(panel) {
+        (k.menu)(app, ui, id);
+    }
+}
+
+/// Per frame, before the panels are drawn: close the panels of libraries that are gone (a User
+/// Defined library whose file was deleted).
+pub fn tidy(app: &mut VectorcraftApp) {
+    for panel in open_panels(&app.ui) {
+        if parse(&panel).is_some_and(|(k, id)| (k.name)(app, id).is_none()) {
+            close(app, &panel);
+        }
+    }
+}
+
+fn close(app: &mut VectorcraftApp, panel: &str) {
+    if let Err(e) = app.run("window.panel.close", json!({ "panel": panel })) {
+        app.status(e);
+    }
+}
+
+/// At startup, after the preferences are restored: the persistent library panels reopen, where the
+/// saved layout has them or floating, their libraries read again (a loaded one from its file; one
+/// that can't be found is left out with a note in the status bar); the others closed with the app.
+pub fn restore(app: &mut VectorcraftApp) {
+    let saved = std::mem::take(&mut app.ui.library_panels);
+    let mut missing = vec![];
+    for mut p in saved.into_iter().filter(|p| p.persistent).take(MAX_PANELS) {
+        let Some(k) = kind(&p.kind) else { continue };
+        if (k.name)(app, &p.id).is_none()
+            && let Some(path) = p.path.clone()
+            // A file now in the user library folder loads as that User Defined library.
+            && let Ok(id) = app.run(k.load, json!({ "path": path })).map(|r| r["library"].as_str().unwrap_or_default().to_string())
+            && id != p.id
+            && rename(&mut app.ui, &p.panel(), &panel_id(k.kind, &id)).is_ok()
+        {
+            p.id = id;
+        }
+        match (k.name)(app, &p.id) {
+            Some(_) => app.ui.library_panels.push(p),
+            None => missing.push(p.path.unwrap_or(p.id)),
+        }
+    }
+    let kept: Vec<String> = app.ui.library_panels.iter().map(LibraryPanel::panel).collect();
+    for panel in open_panels(&app.ui).into_iter().filter(|p| !kept.contains(p)) {
+        close(app, &panel);
+    }
+    app.ui.docking_hidden.retain(|p, _| !p.starts_with(PREFIX) || kept.contains(p));
+    for panel in kept.into_iter().filter(|p| !is_open(&app.ui, p)).collect::<Vec<_>>() {
+        if let Err(e) = float(app, &panel) {
+            missing.push(format!("{panel} ({e})"));
+        }
+    }
+    if !missing.is_empty() {
+        let files = missing.join(", ");
+        app.status(format!("Persistent libraries not found: {files}"));
+    }
+}
+
+/// Replace panel `from` with panel `to` (not open) where it is: in the dock or floating group it
+/// is in, and as the place it goes back to.
+fn rename(ui: &mut UiState, from: &str, to: &str) -> Result<(), String> {
+    fn swap(v: &mut Value, from: &str, to: &str) {
+        match v {
+            Value::String(s) if s == from => *s = to.into(),
+            Value::Array(a) => a.iter_mut().for_each(|v| swap(v, from, to)),
+            Value::Object(o) => o.values_mut().for_each(|v| swap(v, from, to)),
+            _ => {}
+        }
+    }
+    // Panel ids are the only strings of a layout and a location.
+    fn renamed<T: Serialize + serde::de::DeserializeOwned>(t: &T, from: &str, to: &str) -> Result<T, String> {
+        let mut v = serde_json::to_value(t).map_err(|e| e.to_string())?;
+        swap(&mut v, from, to);
+        serde_json::from_value(v).map_err(|e| e.to_string())
+    }
+    registered(to)?;
+    let docking = ui.docking.as_ref().map(|l| renamed(l, from, to)).transpose()?;
+    let mut hidden = std::collections::BTreeMap::new();
+    for (p, at) in &ui.docking_hidden {
+        hidden.insert(if p == from { to.to_string() } else { p.clone() }, renamed(at, from, to)?);
+    }
+    ui.docking = docking;
+    ui.docking_hidden = hidden;
+    for p in ui.floating_panels.iter_mut().flat_map(|g| g.panels.iter_mut()).chain(ui.open_panel.as_mut()).filter(|p| p.as_str() == from) {
+        *p = to.into();
+    }
+    Ok(())
+}
+
+/// The interaction id of the tile or row of `name` in panel `panel`.
+pub(crate) fn tile_id(panel: &str, name: &str) -> egui::Id {
+    egui::Id::new(("library-tile", panel, name))
+}
+
+/// The state key `key` of panel `panel`.
+fn key(panel: &str, key: &str) -> String {
+    format!("{panel}-{key}")
+}
+
 /// The submenu of the libraries menu that lists libraries of `category` (`None`: the top level).
 pub(crate) fn submenu(category: &str) -> Option<&'static str> {
     match category {
@@ -125,22 +370,105 @@ pub(crate) fn library_name<'a>(id: &str, name: &'a str) -> &'a str {
 }
 
 /// The opener of library `K`'s libraries (`window.swatchLibrary {library}`): open library `library`
-/// (an id or a name; `list`: the command listing them) in the panel, `null` closing it. `found`
-/// looks a library up: its id, name and item count. → {open, name, count}
-pub(crate) fn open_command<K: LibraryKind>(
-    app: &mut VectorcraftApp,
-    p: &Value,
-    list: &str,
-    found: impl FnOnce(&VectorcraftApp, &str) -> Option<(String, String, usize)>,
-) -> Result<Value, String> {
+/// (an id or a name) in its own panel, floating, or bring its panel forward when it is open;
+/// `null` closes every panel of `K`'s libraries. → {open, panel, name, count}
+pub(crate) fn open_command<K: LibraryKind>(app: &mut VectorcraftApp, p: &Value) -> Result<Value, String> {
     let Some(key) = p.get("library").filter(|v| !v.is_null()) else {
-        app.ui.library_panel = None;
+        for panel in open_panels(&app.ui).into_iter().filter(|p| parse(p).is_some_and(|(k, _)| k.kind == K::KIND)) {
+            app.run("window.panel.close", json!({ "panel": panel }))?;
+        }
         return Ok(json!({ "open": null }));
     };
+    let list = K::LIST;
     let key = key.as_str().ok_or_else(|| format!("`library` is a library id or name (see {list})"))?;
-    let (id, name, count) = found(app, key).ok_or_else(|| format!("no library `{key}` (see {list})"))?;
-    app.ui.library_panel = Some(OpenLibrary { kind: K::KIND.into(), id: id.clone() });
-    Ok(json!({"open": id, "name": name, "count": count}))
+    let (id, name, count) = K::find(app, key).ok_or_else(|| format!("no library `{key}` (see {list})"))?;
+    let panel = panel_id(K::KIND, &id);
+    registered(&panel)?;
+    // Brought forward, it is the one opened last.
+    let at = app.ui.library_panels.iter().position(|q| q.kind == K::KIND && q.id == id);
+    if let Some(s) = at.map(|i| app.ui.library_panels.remove(i)) {
+        app.ui.library_panels.push(s);
+    }
+    settings_mut(app, kind_of::<K>(), &id);
+    if is_open(&app.ui, &panel) {
+        app.run("window.panel.activate", json!({ "panel": panel }))?;
+    } else {
+        float(app, &panel)?;
+    }
+    Ok(json!({"open": id, "panel": panel, "name": name, "count": count}))
+}
+
+/// Float library panel `panel`, as tall as its body in the kind's view.
+pub(crate) fn float(app: &mut VectorcraftApp, panel: &str) -> Result<Value, String> {
+    let large = parse(panel).is_some_and(|(k, _)| k.view == View::LargeThumb);
+    app.run("window.panel.float", json!({ "panel": panel, "height": if large { 400 } else { 340 } }))
+}
+
+/// `ui.libraryPanel {panel, library?, view?, showFind?, persistent?}`: show another library in an
+/// open library panel (Previous / Next Library; one open in a panel of its own is brought forward
+/// instead), and set a panel's view, Show Find Field and Persistent (also a closed persistent one's).
+/// → its settings
+pub(crate) fn command(app: &mut VectorcraftApp, p: &Value) -> Result<Value, String> {
+    let given = p.get("panel").and_then(Value::as_str).unwrap_or_default();
+    let (k, id) = parse(given).ok_or_else(|| format!("`{given}` isn't a library panel (see window.swatchLibrary)"))?;
+    let mut id = id.to_string();
+    let open = is_open(&app.ui, given);
+    let closed = || format!("library panel `{given}` isn't open");
+    if !open && !settings(&app.ui, k.kind, &id).is_some_and(|s| s.persistent) {
+        return Err(closed());
+    }
+    let view = match p.get("view") {
+        None | Some(Value::Null) => None,
+        Some(v) => Some(
+            serde_json::from_value::<View>(v.clone())
+                .map_err(|_| "`view` is smallThumb, mediumThumb, largeThumb, smallList or largeList".to_string())?,
+        ),
+    };
+    let show_find = crate::menus::opt_bool(p, "showFind")?;
+    let persistent = crate::menus::opt_bool(p, "persistent")?;
+    if let Some(key) = p.get("library").filter(|v| !v.is_null()) {
+        let list = k.list;
+        let key = key.as_str().ok_or_else(|| format!("`library` is a library id or name (see {list})"))?;
+        let (next, ..) = (k.find)(app, key).ok_or_else(|| format!("no library `{key}` (see {list})"))?;
+        // Only an open panel shows another library.
+        if !open {
+            return Err(closed());
+        }
+        let to = panel_id(k.kind, &next);
+        if is_open(&app.ui, &to) {
+            app.run("window.panel.activate", json!({ "panel": to }))?;
+        } else if next != id {
+            rename(&mut app.ui, given, &to)?;
+            app.ui.library_panels.retain(|q| !(q.kind == k.kind && q.id == next));
+            let path = if next.starts_with("loaded/") { (k.path)(app, &next) } else { None };
+            if let Some(s) = settings_mut(app, k, &id) {
+                (s.id, s.path) = (next.clone(), path);
+            }
+        }
+        id = next;
+    }
+    let s = settings_mut(app, k, &id).ok_or_else(closed)?;
+    s.view = view.or(s.view);
+    s.hide_find = show_find.map_or(s.hide_find, |show| !show);
+    s.persistent = persistent.unwrap_or(s.persistent);
+    let s = s.clone();
+    Ok(json!({
+        "panel": s.panel(),
+        "kind": s.kind,
+        "library": s.id,
+        "view": s.view.unwrap_or(k.view),
+        "showFind": !s.hide_find,
+        "persistent": s.persistent,
+        "open": is_open(&app.ui, &s.panel()),
+    }))
+}
+
+/// Run `ui.libraryPanel` on panel `panel` with `params`.
+fn set(app: &mut VectorcraftApp, panel: &str, mut params: Value) {
+    params["panel"] = json!(panel);
+    if let Err(e) = app.run("ui.libraryPanel", params) {
+        app.status(e);
+    }
 }
 
 /// Other Library…: the library file at `path`, else one picked in an open dialog; `None` when the
@@ -167,73 +495,28 @@ pub(crate) fn user_slot(id: &str, prefix: &str, libraries: Vec<LibraryInfo>) ->
     libraries.into_iter().filter(|l| l.category == "user").nth(n.checked_sub(1)?)
 }
 
-/// The panel's window: a tab strip with the library's name, the panel menu and a close button, then
-/// the body. A library that no longer exists closes it.
-fn window<K: LibraryKind>(app: &mut VectorcraftApp, ctx: &egui::Context, id: &str) {
-    let Some((name, lib)) = K::get(app, id) else {
-        app.ui.library_panel = None;
-        return;
-    };
-    let t = Tokens::get(ctx);
-    let mut open = true;
-    // Left of the icon panels' pop-out, movable.
-    let at = egui::pos2((ctx.content_rect().right() - 880.0).max(8.0), 140.0);
-    let area =
-        egui::Area::new(egui::Id::new(("library-panel", K::KIND))).order(egui::Order::Foreground).default_pos(at).movable(true).constrain(true);
-    area.show(ctx, |ui| {
-        egui::Frame::popup(ui.style()).fill(t.panel).corner_radius(CornerRadius::same(4)).inner_margin(egui::Margin::ZERO).show(ui, |ui| {
-            ui.set_width(256.0);
-            let (strip, _) = ui.allocate_exact_size(vec2(256.0, 26.0), Sense::hover());
-            ui.painter().rect_filled(strip, CornerRadius { nw: 4, ne: 4, sw: 0, se: 0 }, t.panel_darker);
-            let name = library_name(id, &name);
-            let label = egui::RichText::new(name).font(theme::semibold(12.0));
-            let galley = ui.painter().layout_no_wrap(name.to_string(), theme::semibold(12.0), t.text);
-            let tab = Rect::from_min_size(strip.min, vec2((galley.size().x + 24.0).min(190.0), 26.0));
-            ui.painter().rect_filled(tab, CornerRadius { nw: 4, ne: 0, sw: 0, se: 0 }, t.panel);
-            ui.put(tab.shrink2(vec2(12.0, 0.0)), egui::Label::new(label.color(t.text)).truncate().selectable(false));
-            let close = Rect::from_center_size(strip.right_center() - vec2(13.0, 0.0), vec2(14.0, 14.0));
-            let cr = ui.interact(close, ui.id().with("close-library"), Sense::click()).on_hover_text(tl!("Close"));
-            icons::paint(ui, "x", close, if cr.hovered() { t.text } else { t.text_dim });
-            open = !cr.clicked();
-            let menu = Rect::from_center_size(strip.right_center() - vec2(34.0, 0.0), vec2(16.0, 16.0));
-            let mr = ui.interact(menu, ui.id().with("library-menu"), Sense::click()).on_hover_text(tl!("Panel menu"));
-            icons::paint(ui, "menu", menu.shrink(1.0), if mr.hovered() { t.text_strong } else { t.text_dim });
-            egui::Popup::menu(&mr).show(|ui| {
-                ui.set_min_width(200.0);
-                panel_menu::<K>(app, ui, id);
-            });
-            egui::Frame::NONE.inner_margin(egui::Margin::same(10)).show(ui, |ui| {
-                ui.set_width(236.0);
-                body::<K>(app, ui, id, &lib);
-            });
-        });
-    });
-    if !open {
-        app.ui.library_panel = None;
-    }
+/// Test frames: the panel opened last, as the dock or a floating group draws its body.
+#[cfg(test)]
+pub(crate) fn show_window(app: &mut VectorcraftApp, ctx: &egui::Context) {
+    let Some(panel) = last_open(&app.ui).map(LibraryPanel::panel) else { return };
+    let area = egui::Area::new(egui::Id::new("test-library-panel")).fixed_pos(egui::pos2(20.0, 20.0));
+    area.show(ctx, |ui| crate::dock::panel_body(app, ui, &panel, 256.0, 400.0));
 }
 
-/// The selected items and folders of library `id` (a selection in another library is dropped).
-fn selection<K: LibraryKind>(ctx: &egui::Context, id: &str) -> Vec<String> {
-    let (lib, sel): (String, Vec<String>) = pstate(ctx, &key::<K>("selected"));
-    if lib == id { sel } else { vec![] }
+/// The selected items and folders of panel `panel`.
+fn selection(ctx: &egui::Context, panel: &str) -> Vec<String> {
+    pstate(ctx, &key(panel, "selected"))
 }
 
-fn set_selection<K: LibraryKind>(ctx: &egui::Context, id: &str, sel: Vec<String>) {
-    set_pstate(ctx, &key::<K>("selected"), (id.to_string(), sel));
-}
-
-/// Find field, thumbnails or list rows, and the bottom bar.
-fn body<K: LibraryKind>(app: &mut VectorcraftApp, ui: &mut Ui, id: &str, lib: &K::Lib) {
-    let view = view::<K>(ui.ctx());
-    let query = if pstate::<bool>(ui.ctx(), &key::<K>("hide-find")) {
-        String::new()
-    } else {
-        widgets::search_field(ui, egui::Id::new(key::<K>("find")), tl!("Find"))
-    };
+/// Find field, thumbnails or list rows, and the bottom bar of library `id`'s panel.
+fn body<K: LibraryKind>(app: &mut VectorcraftApp, ui: &mut Ui, id: &str) {
+    let Some((_, lib)) = K::get(app, id) else { return };
+    let panel = panel_id(K::KIND, id);
+    let (view, hide_find) = settings(&app.ui, K::KIND, id).map_or((K::VIEW, false), |s| (s.view.unwrap_or(K::VIEW), s.hide_find));
+    let query = if hide_find { String::new() } else { widgets::search_field(ui, egui::Id::new(key(&panel, "find")), tl!("Find")) };
     ui.add_space(4.0);
-    let rows = K::rows(lib, &query.trim().to_lowercase());
-    let selected = selection::<K>(ui.ctx(), id);
+    let rows = K::rows(&lib, &query.trim().to_lowercase());
+    let selected = selection(ui.ctx(), &panel);
     let is_sel = |n: &str| selected.iter().any(|s| s == n);
     let mut clicked: Option<(String, bool, egui::Modifiers)> = None;
     let mut click = |ui: &Ui, resp: egui::Response, row: &Row<K::Item>, tip: &dyn Fn() -> String| {
@@ -243,13 +526,13 @@ fn body<K: LibraryKind>(app: &mut VectorcraftApp, ui: &mut Ui, id: &str, lib: &K
     };
     widgets::list_box(ui, |ui| {
         let max_height = if view == View::LargeThumb { 280.0 } else { 220.0 };
-        egui::ScrollArea::vertical().id_salt(key::<K>("scroll")).max_height(max_height).show(ui, |ui| {
+        egui::ScrollArea::vertical().id_salt(key(&panel, "scroll")).max_height(max_height).show(ui, |ui| {
             ui.set_width(ui.available_width());
             if rows.is_empty() {
                 widgets::dim_label(ui, if query.trim().is_empty() { tl!("This library is empty.") } else { tl!("No matches.") });
             } else if view.is_list() {
                 for row in &rows {
-                    let (r, resp, chip) = list_row(ui, tile_id::<K>(row.name), view, is_sel(row.name));
+                    let (r, resp, chip) = list_row(ui, tile_id(&panel, row.name), view, is_sel(row.name));
                     match row.item {
                         Some(item) => {
                             K::draw(app, ui, chip, item, false, false);
@@ -263,7 +546,7 @@ fn body<K: LibraryKind>(app: &mut VectorcraftApp, ui: &mut Ui, id: &str, lib: &K
                 }
             } else {
                 for (row, cell) in tile_grid(ui, &rows, view, |r| r.item.is_none()) {
-                    let resp = ui.interact(cell, tile_id::<K>(row.name), Sense::click());
+                    let resp = ui.interact(cell, tile_id(&panel, row.name), Sense::click());
                     match row.item {
                         Some(item) => K::draw(app, ui, cell, item, is_sel(row.name), resp.hovered()),
                         None => folder_tile(ui, cell, is_sel(row.name)),
@@ -277,8 +560,8 @@ fn body<K: LibraryKind>(app: &mut VectorcraftApp, ui: &mut Ui, id: &str, lib: &K
         // A plain click on an item also adds and applies it; folders and modifier clicks only select.
         let only_select = folder || m.shift || m.command;
         let order: Vec<&str> = rows.iter().map(|r| r.name).collect();
-        let sel = click_selection(ui, &key::<K>("anchor"), selected, &order, &name, m);
-        set_selection::<K>(ui.ctx(), id, sel);
+        let sel = click_selection(ui, &key(&panel, "anchor"), selected, &order, &name, m);
+        set_pstate(ui.ctx(), &key(&panel, "selected"), sel);
         if !only_select {
             K::click(app, ui, id, &name);
         }
@@ -294,7 +577,14 @@ fn neighbour<K: LibraryKind>(app: &VectorcraftApp, id: &str, step: isize) -> Opt
     all.into_iter().nth((i + step).rem_euclid(n) as usize).map(|l| l.id)
 }
 
-/// Open library `id` in the panel.
+/// Show the library `step` places after (or before) `id` in its panel.
+fn step<K: LibraryKind>(app: &mut VectorcraftApp, id: &str, step: isize) {
+    if let Some(next) = neighbour::<K>(app, id, step) {
+        set(app, &panel_id(K::KIND, id), json!({ "library": next }));
+    }
+}
+
+/// Open library `id` in its panel.
 fn open<K: LibraryKind>(app: &mut VectorcraftApp, id: &str) {
     if let Err(e) = app.run(K::OPEN, json!({ "library": id })) {
         app.status(e);
@@ -303,18 +593,16 @@ fn open<K: LibraryKind>(app: &mut VectorcraftApp, id: &str) {
 
 /// Libraries menu, previous / next library, and Add to … for the selection.
 fn bottom<K: LibraryKind>(app: &mut VectorcraftApp, ui: &mut Ui, id: &str) {
-    let selected = selection::<K>(ui.ctx(), id);
+    let selected = selection(ui.ctx(), &panel_id(K::KIND, id));
     widgets::bottom_bar(ui, |ui| {
         let r = widgets::icon_button(ui, "library", K::MENU, false, 24.0);
         egui::Popup::menu(&r).show(|ui| {
             ui.set_min_width(200.0);
             library_menu::<K>(app, ui);
         });
-        for (icon, tip, step) in [("chevron-left", tl!("Previous Library"), -1), ("chevron-right", tl!("Next Library"), 1)] {
-            if widgets::icon_button(ui, icon, tip, false, 24.0).clicked()
-                && let Some(next) = neighbour::<K>(app, id, step)
-            {
-                open::<K>(app, &next);
+        for (icon, tip, s) in [("chevron-left", tl!("Previous Library"), -1), ("chevron-right", tl!("Next Library"), 1)] {
+            if widgets::icon_button(ui, icon, tip, false, 24.0).clicked() {
+                step::<K>(app, id, s);
             }
         }
         ui.add_space((ui.available_width() - 28.0).max(0.0));
@@ -324,54 +612,56 @@ fn bottom<K: LibraryKind>(app: &mut VectorcraftApp, ui: &mut Ui, id: &str) {
     });
 }
 
-/// The library panel's (≡) menu.
+/// A library panel's (≡) menu.
 fn panel_menu<K: LibraryKind>(app: &mut VectorcraftApp, ui: &mut Ui, id: &str) {
-    let selected = selection::<K>(ui.ctx(), id);
+    let panel = panel_id(K::KIND, id);
+    let selected = selection(ui.ctx(), &panel);
     if menu_item(ui, K::ADD, !selected.is_empty(), false) {
         K::add(app, id, selected);
     }
     ui.separator();
-    let view = view::<K>(ui.ctx());
+    let s = settings(&app.ui, K::KIND, id);
+    let (view, hide_find, persistent) = s.map_or((K::VIEW, false, false), |s| (s.view.unwrap_or(K::VIEW), s.hide_find, s.persistent));
     for (v, label) in View::ALL {
         if menu_item(ui, label, true, v == view) {
-            set_pstate(ui.ctx(), &key::<K>("view"), Some(v));
+            set(app, &panel, json!({ "view": v }));
         }
     }
     ui.separator();
-    let hidden: bool = pstate(ui.ctx(), &key::<K>("hide-find"));
-    if menu_item(ui, tl!("Show Find Field"), true, !hidden) {
-        set_pstate(ui.ctx(), &key::<K>("hide-find"), !hidden);
+    if menu_item(ui, tl!("Show Find Field"), true, !hide_find) {
+        set(app, &panel, json!({ "showFind": hide_find }));
     }
     ui.separator();
-    for (label, step) in [(tl!("Previous Library"), -1), (tl!("Next Library"), 1)] {
-        if menu_item(ui, label, true, false)
-            && let Some(next) = neighbour::<K>(app, id, step)
-        {
-            open::<K>(app, &next);
+    for (label, s) in [(tl!("Previous Library"), -1), (tl!("Next Library"), 1)] {
+        if menu_item(ui, label, true, false) {
+            step::<K>(app, id, s);
         }
     }
+    if menu_item(ui, tl!("Persistent"), true, persistent) {
+        set(app, &panel, json!({ "persistent": !persistent }));
+    }
     if menu_item(ui, tl!("Close Library"), true, false) {
-        app.ui.library_panel = None;
+        close(app, &panel);
     }
 }
 
-/// The libraries menu (the panel's library button, the Swatches panel's): every library by
-/// submenu, the open one checked, between `K`'s head and tail items.
+/// The libraries menu (a library panel's library button, the Swatches panel's): every library by
+/// submenu, the open ones checked, between `K`'s head and tail items.
 pub(crate) fn library_menu<K: LibraryKind>(app: &mut VectorcraftApp, ui: &mut Ui) {
     K::menu_head(app, ui);
-    let current = app.ui.library_panel.as_ref().filter(|o| o.kind == K::KIND).map(|o| o.id.clone());
-    if let Some(id) = library_items(ui, &K::list(app), current.as_deref()) {
+    let shown = open_panels(&app.ui);
+    if let Some(id) = library_items(ui, &K::list(app), &|id| shown.contains(&panel_id(K::KIND, id))) {
         open::<K>(app, &id);
     }
     K::menu_tail(app, ui);
 }
 
-/// Menu rows for `libs`: the top-level ones, then a submenu per [`LibraryRef::submenu`], with
-/// `current` checked. Returns the id of the one clicked.
-pub(crate) fn library_items(ui: &mut Ui, libs: &[LibraryRef], current: Option<&str>) -> Option<String> {
+/// Menu rows for `libs`: the top-level ones, then a submenu per [`LibraryRef::submenu`], those
+/// `checked` says checked. Returns the id of the one clicked.
+pub(crate) fn library_items(ui: &mut Ui, libs: &[LibraryRef], checked: &dyn Fn(&str) -> bool) -> Option<String> {
     let mut chosen = None;
     let mut item = |ui: &mut Ui, l: &LibraryRef| {
-        if widgets::menu_item_name(ui, library_name(&l.id, &l.name), true, current == Some(l.id.as_str())) {
+        if widgets::menu_item_name(ui, library_name(&l.id, &l.name), true, checked(&l.id)) {
             chosen = Some(l.id.clone());
         }
     };
@@ -398,7 +688,7 @@ pub(crate) fn library_items(ui: &mut Ui, libs: &[LibraryRef], current: Option<&s
 
 #[cfg(test)]
 mod tests {
-    use egui::{Event, Modifiers, PointerButton, Pos2};
+    use egui::{Event, Modifiers, PointerButton, Pos2, vec2};
     use serde_json::Value;
     use vectorcraft_color::Paint;
     use vectorcraft_engine::Session;
@@ -427,12 +717,17 @@ mod tests {
         out.textures_delta.clear();
     }
 
-    /// Click the tile or row of `name` with `modifiers` (frames from `time` to `time + 0.5`; a new
-    /// window takes a sizing frame first).
+    /// The panel opened last.
+    fn shown(app: &VectorcraftApp) -> String {
+        last_open(&app.ui).expect("a library panel is open").panel()
+    }
+
+    /// Click the tile or row of `name` in the panel opened last with `modifiers` (frames from
+    /// `time` to `time + 0.5`; a new window takes a sizing frame first).
     fn click(app: &mut VectorcraftApp, ctx: &egui::Context, name: &str, modifiers: Modifiers, time: f64) {
         frame(app, ctx, vec![], Modifiers::NONE, time);
         frame(app, ctx, vec![], Modifiers::NONE, time + 0.25);
-        let at = ctx.read_response(tile_id::<SwatchLibraries>(name)).unwrap_or_else(|| panic!("no tile for {name}")).rect.center();
+        let at = ctx.read_response(tile_id(&shown(app), name)).unwrap_or_else(|| panic!("no tile for {name}")).rect.center();
         let button = |pressed| Event::PointerButton { pos: at, button: PointerButton::Primary, pressed, modifiers };
         frame(app, ctx, vec![Event::PointerMoved(at), button(true), button(false)], modifiers, time + 0.5);
     }
@@ -446,8 +741,8 @@ mod tests {
         let mut app = app();
         let ctx = context();
         let r = app.run("window.swatchLibrary", json!({"library": "Pastels"})).unwrap();
-        assert_eq!((r["open"].as_str(), r["count"].as_u64()), (Some("pastels"), Some(24)));
-        assert_eq!(app.ui.library_panel, Some(OpenLibrary { kind: "swatches".into(), id: "pastels".into() }));
+        assert_eq!((r["open"].as_str(), r["count"].as_u64(), r["panel"].as_str()), (Some("pastels"), Some(24), Some("library:swatches:pastels")));
+        assert_eq!(last_open(&app.ui).map(|p| (p.kind.as_str(), p.id.as_str())), Some(("swatches", "pastels")));
         let undo = undo_len(&app);
         click(&mut app, &ctx, "Pastel Teal", Modifiers::NONE, 0.0);
         let d = &app.session.doc().unwrap().doc;
@@ -459,10 +754,10 @@ mod tests {
         let blue = app.session.doc().unwrap().doc.swatch("Soft Blue").and_then(|w| w.paint.color()).unwrap();
         assert_eq!(app.session.paint.stroke.color(), Some(blue));
         assert!(app.session.fill_active, "Alt keeps the active proxy");
-        // A library that doesn't exist closes the panel; null closes it.
+        // A library that doesn't exist is an error; null closes the panel.
         assert!(app.run("window.swatchLibrary", json!({"library": "nope"})).is_err());
         app.run("window.swatchLibrary", json!({"library": null})).unwrap();
-        assert!(app.ui.library_panel.is_none());
+        assert!(last_open(&app.ui).is_none());
     }
 
     #[test]
@@ -472,17 +767,17 @@ mod tests {
         app.run("window.swatchLibrary", json!({"library": "earth-tones"})).unwrap();
         click(&mut app, &ctx, "Clay 1", Modifiers::COMMAND, 0.0);
         click(&mut app, &ctx, "Ochre", Modifiers::NONE, 2.0);
-        assert_eq!(selection::<SwatchLibraries>(&ctx, "earth-tones"), ["Ochre"], "a folder click selects its group");
+        assert_eq!(selection(&ctx, "library:swatches:earth-tones"), ["Ochre"], "a folder click selects its group");
         click(&mut app, &ctx, "Clay 3", Modifiers::COMMAND, 4.0);
         assert!(app.session.doc().unwrap().doc.swatch("Clay 3").is_none(), "modifier clicks only select");
-        let sel = selection::<SwatchLibraries>(&ctx, "earth-tones");
+        let sel = selection(&ctx, "library:swatches:earth-tones");
         SwatchLibraries::add(&mut app, "earth-tones", sel);
         let d = &app.session.doc().unwrap().doc;
         assert_eq!(d.swatch_groups.iter().find(|g| g.name == "Ochre").map(|g| g.swatches.len()), Some(6));
         assert!(d.swatches.iter().any(|w| w.name == "Clay 3"));
-        // The selection belongs to its library.
+        // The selection belongs to its library's panel.
         app.run("window.swatchLibrary", json!({"library": "brights"})).unwrap();
-        assert!(selection::<SwatchLibraries>(&ctx, "brights").is_empty());
+        assert!(selection(&ctx, "library:swatches:brights").is_empty());
     }
 
     #[test]
@@ -494,12 +789,12 @@ mod tests {
         let order: Vec<String> = SwatchLibraries::rows(&lib, "").iter().map(|r| r.name.to_string()).collect();
         click(&mut app, &ctx, &order[1], Modifiers::NONE, 0.0);
         click(&mut app, &ctx, &order[4], Modifiers::SHIFT, 2.0);
-        assert_eq!(selection::<SwatchLibraries>(&ctx, "pastels"), order[1..=4], "the range starts at the plain click");
+        assert_eq!(selection(&ctx, "library:swatches:pastels"), order[1..=4], "the range starts at the plain click");
         // A plain click after a Cmd/Ctrl-click moves the anchor from the Cmd/Ctrl-clicked item.
         click(&mut app, &ctx, &order[8], Modifiers::COMMAND, 4.0);
         click(&mut app, &ctx, &order[2], Modifiers::NONE, 6.0);
         click(&mut app, &ctx, &order[3], Modifiers::SHIFT, 8.0);
-        assert_eq!(selection::<SwatchLibraries>(&ctx, "pastels"), order[2..=3]);
+        assert_eq!(selection(&ctx, "library:swatches:pastels"), order[2..=3]);
         let d = &app.session.doc().unwrap().doc;
         assert!(d.swatch(&order[2]).is_some(), "a plain click still adds the swatch");
         assert!(d.swatch(&order[3]).is_none(), "a Shift-click only selects");
@@ -510,12 +805,13 @@ mod tests {
         let mut app = app();
         let ctx = context();
         app.run("window.swatchLibrary", json!({"library": "web-safe-216"})).unwrap();
-        set_pstate(&ctx, &key::<SwatchLibraries>("view"), Some(View::SmallList));
-        ctx.data_mut(|d| d.insert_temp(egui::Id::new(key::<SwatchLibraries>("find")), "#FF00".to_string()));
+        let panel = "library:swatches:web-safe-216";
+        app.run("ui.libraryPanel", json!({"panel": panel, "view": "smallList"})).unwrap();
+        ctx.data_mut(|d| d.insert_temp(egui::Id::new(key(panel, "find")), "#FF00".to_string()));
         frame(&mut app, &ctx, vec![], Modifiers::NONE, 0.0);
         frame(&mut app, &ctx, vec![], Modifiers::NONE, 0.5);
-        assert!(ctx.read_response(tile_id::<SwatchLibraries>("#FF0033")).is_some());
-        assert!(ctx.read_response(tile_id::<SwatchLibraries>("#00FF00")).is_none());
+        assert!(ctx.read_response(tile_id(panel, "#FF0033")).is_some());
+        assert!(ctx.read_response(tile_id(panel, "#00FF00")).is_none());
         let first = SWATCH_IDS[0];
         let last = SwatchLibraries::list(&app).pop().unwrap().id;
         assert_eq!(last, "radial-glows", "gradient libraries come after the swatch libraries");
@@ -585,7 +881,7 @@ mod tests {
         assert!(app.ui.dialog.is_none());
         assert_eq!(user_items(&app), [("Loud".to_string(), "window.userSwatchLibrary1".to_string())]);
         app.run("window.userSwatchLibrary1", json!({})).unwrap();
-        assert_eq!(app.ui.library_panel.as_ref().map(|o| o.id.as_str()), Some("user/Loud.vcswatches"));
+        assert_eq!(last_open(&app.ui).map(|p| p.id.as_str()), Some("user/Loud.vcswatches"));
         let (_, lib) = SwatchLibraries::get(&app, "user/Loud.vcswatches").unwrap();
         assert_eq!((lib.groups.len(), lib.len()), (1, 5), "only the selected group");
         let _ = std::fs::remove_dir_all(dir);
@@ -625,7 +921,7 @@ mod tests {
         );
         // Opening a palette file opens it in the library panel.
         crate::io::open_bytes(&mut app, "Saved.gpl", text.as_bytes(), None).unwrap();
-        let open = app.ui.library_panel.clone().unwrap();
+        let open = last_open(&app.ui).cloned().unwrap();
         assert!(open.id.starts_with("loaded/"), "{open:?}");
         assert_eq!(app.session.documents().len(), 1, "not opened as a document");
         let other = SwatchLibraries::list(&app).into_iter().find(|l| l.id == open.id).unwrap();
@@ -688,10 +984,160 @@ mod tests {
         // A file opened on the web has no path; open_bytes passes its bytes as dataBase64.
         let mut app = app();
         crate::io::open_bytes(&mut app, "Brand.ase", &vectorcraft_testkit::ase::sample(), None).unwrap();
-        let open = app.ui.library_panel.clone().unwrap();
+        let open = last_open(&app.ui).cloned().unwrap();
         assert_eq!(open.id, "loaded/Brand.ase");
         let (_, lib) = SwatchLibraries::get(&app, &open.id).unwrap();
         assert_eq!((lib.len(), lib.groups.len()), (4, 1));
         assert_eq!(app.session.documents().len(), 1, "not opened as a document");
     }
+
+    fn docking(app: &VectorcraftApp) -> &craft_ui::docking::Layout<String> {
+        app.ui.docking.as_ref().expect("library panels live in the shared layout")
+    }
+
+    fn panel_of(reply: Value) -> String {
+        reply["panel"].as_str().expect("the reply names the panel").to_string()
+    }
+
+    fn groups(app: &VectorcraftApp) -> Vec<Vec<String>> {
+        docking(app).floating.iter().map(|g| g.panels.clone()).collect()
+    }
+
+    #[test]
+    fn each_library_opens_in_a_panel_of_its_own() {
+        let mut app = app();
+        // Without the shared layout yet, `window.panel` floats a library panel too.
+        app.run("window.panel", json!({"panel": "library:swatches:earth-tones"})).unwrap();
+        assert!(is_open(&app.ui, "library:swatches:earth-tones"));
+        app.run("window.panel.close", json!({"panel": "library:swatches:earth-tones"})).unwrap();
+        let pastels = panel_of(app.run("window.swatchLibrary", json!({"library": "pastels"})).unwrap());
+        let brights = panel_of(app.run("window.swatchLibrary", json!({"library": "Brights"})).unwrap());
+        let styles = panel_of(app.run("window.graphicStyleLibrary", json!({"library": "hand-drawn"})).unwrap());
+        assert_eq!([&pastels, &brights, &styles], ["library:swatches:pastels", "library:swatches:brights", "library:graphicStyles:hand-drawn"]);
+        assert_eq!(groups(&app), [vec![pastels.clone()], vec![brights.clone()], vec![styles.clone()]], "each floats on its own");
+        assert_ne!(docking(&app).floating[0].rect, docking(&app).floating[1].rect, "one beside another");
+        assert_eq!(tab_label(&app, &brights).as_deref(), Some("Brights"));
+        // Opening an open library brings its panel forward.
+        app.run("window.swatchLibrary", json!({"library": "pastels"})).unwrap();
+        assert_eq!(groups(&app).len(), 3);
+        assert_eq!(last_open(&app.ui).map(LibraryPanel::panel), Some(pastels.clone()));
+        // They group, dock and close as any panel, and `window.panel` shows one again.
+        app.run("window.panel.float", json!({"panel": brights, "onto": pastels})).unwrap();
+        assert!(groups(&app).contains(&vec![pastels.clone(), brights.clone()]), "{:?}", groups(&app));
+        app.run("window.panel.dock", json!({"panel": styles})).unwrap();
+        assert!(craft_ui::docking::Layout { root: docking(&app).root.clone(), floating: vec![] }.contains(&styles));
+        app.run("window.panel.close", json!({"panel": brights})).unwrap();
+        assert!(!is_open(&app.ui, &brights) && is_open(&app.ui, &pastels));
+        app.run("window.panel", json!({"panel": brights})).unwrap();
+        assert!(is_open(&app.ui, &brights));
+        assert!(crate::panel_docking::valid(docking(&app)));
+        // `library: null` closes the panels of its kind.
+        app.run("window.swatchLibrary", json!({"library": null})).unwrap();
+        assert!(!any_open::<SwatchLibraries>(&app.ui) && is_open(&app.ui, &styles));
+        // What isn't a library panel's id.
+        for bad in ["library:nope:x", "library:swatches:", "library:swatches", "Library:swatches:pastels"] {
+            assert!(crate::menus::normalize_panel(bad).is_none(), "{bad}");
+        }
+        assert!(app.run("ui.libraryPanel", json!({"panel": "layers"})).is_err());
+        assert!(app.run("ui.libraryPanel", json!({"panel": pastels, "persistent": true})).is_err(), "closed and not persistent");
+        assert!(app.run("ui.libraryPanel", json!({"panel": styles, "view": "huge"})).is_err());
+    }
+
+    /// The app restarted with the preferences `app` saves.
+    fn restarted(app: &VectorcraftApp) -> VectorcraftApp {
+        let saved: crate::UiState = serde_json::from_slice(&serde_json::to_vec(&app.ui).unwrap()).unwrap();
+        let mut next = VectorcraftApp::new(Session::new(), Default::default());
+        next.ui = saved.sanitized();
+        restore(&mut next);
+        next
+    }
+
+    #[test]
+    fn persistent_panels_reopen_at_startup_with_their_settings() {
+        let dir = std::env::temp_dir().join(format!("vc-persistent-libraries-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+        let gpl = dir.join("Brand.gpl");
+        std::fs::write(&gpl, "GIMP Palette\nName: Brand\n#\n255   0   0\tRed\n").unwrap();
+        let mut app = app();
+        let pastels = panel_of(app.run("window.swatchLibrary", json!({"library": "pastels"})).unwrap());
+        let brights = panel_of(app.run("window.swatchLibrary", json!({"library": "brights"})).unwrap());
+        let brand = panel_of(app.run("window.swatchLibrary.other", json!({"path": gpl.to_string_lossy()})).unwrap());
+        let r = app.run("ui.libraryPanel", json!({"panel": pastels, "persistent": true, "view": "largeList", "showFind": false})).unwrap();
+        assert_eq!((r["persistent"].as_bool(), r["view"].as_str(), r["showFind"].as_bool()), (Some(true), Some("largeList"), Some(false)));
+        app.run("ui.libraryPanel", json!({"panel": brand, "persistent": true})).unwrap();
+        app.run("window.panel.float", json!({"panel": pastels, "x": 40, "y": 90})).unwrap();
+        // A persistent panel reopens even when it was closed.
+        app.run("window.panel.close", json!({"panel": brand})).unwrap();
+        let next = restarted(&app);
+        assert!(is_open(&next.ui, &pastels) && is_open(&next.ui, &brand), "{}", next.ui.status);
+        assert!(!is_open(&next.ui, &brights), "a panel that isn't persistent closed with the app");
+        let group = docking(&next).floating.iter().find(|g| g.panels.contains(&pastels)).unwrap();
+        assert_eq!(group.rect[..2], [40.0, 90.0], "where it was");
+        let s = settings(&next.ui, "swatches", "pastels").unwrap();
+        assert_eq!((s.view, s.hide_find, s.persistent), (Some(View::LargeList), true, true));
+        let (_, id) = parse(&brand).unwrap();
+        assert!(SwatchLibraries::get(&next, id).is_some_and(|(_, lib)| lib.swatch("Red").is_some()), "read again from its file");
+        assert!(next.ui.status.is_empty(), "{}", next.ui.status);
+        assert!(next.ui.docking_hidden.keys().all(|p| p != &brights));
+        // Unchecked, a panel no longer reopens; a file that is gone is left out with a note.
+        let mut next = next;
+        next.run("ui.libraryPanel", json!({"panel": pastels, "persistent": false})).unwrap();
+        std::fs::remove_file(&gpl).unwrap();
+        let last = restarted(&next);
+        assert!(!is_open(&last.ui, &pastels) && !is_open(&last.ui, &brand));
+        assert!(last.ui.status.contains("Brand.gpl"), "{}", last.ui.status);
+        assert!(last.ui.library_panels.is_empty());
+        let _ = std::fs::remove_dir_all(dir);
+    }
+
+    #[test]
+    fn previous_and_next_show_the_neighbouring_library_in_the_same_panel() {
+        let mut app = app();
+        let first = panel_of(app.run("window.swatchLibrary", json!({"library": "pastels"})).unwrap());
+        app.run("window.panel.float", json!({"panel": first, "x": 50, "y": 60})).unwrap();
+        app.run("ui.libraryPanel", json!({"panel": first, "persistent": true, "view": "smallList"})).unwrap();
+        step::<SwatchLibraries>(&mut app, "pastels", 1);
+        let next = panel_id("swatches", SWATCH_IDS[5]);
+        assert!(!is_open(&app.ui, &first) && is_open(&app.ui, &next), "{}", app.ui.status);
+        let group = docking(&app).floating.iter().find(|g| g.panels.contains(&next)).unwrap();
+        assert_eq!((group.panels.len(), group.rect[0], group.rect[1]), (1, 50.0, 60.0), "in its place");
+        let s = settings(&app.ui, "swatches", SWATCH_IDS[5]).unwrap();
+        assert_eq!((s.view, s.persistent), (Some(View::SmallList), true), "the panel keeps its settings");
+        assert!(settings(&app.ui, "swatches", "pastels").is_none());
+        assert!(crate::panel_docking::valid(docking(&app)));
+        // A library open in a panel of its own is brought forward instead.
+        app.run("window.swatchLibrary", json!({"library": "pastels"})).unwrap();
+        let r = app.run("ui.libraryPanel", json!({"panel": next, "library": "Pastels"})).unwrap();
+        assert_eq!(r["panel"], json!(first));
+        assert!(is_open(&app.ui, &next) && is_open(&app.ui, &first));
+    }
+
+    #[test]
+    fn a_panel_closes_when_its_library_is_gone() {
+        let dir = std::env::temp_dir().join(format!("vc-gone-library-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+        std::fs::write(dir.join("Gone.gpl"), "GIMP Palette\nName: Gone\n#\n0 0 0\tInk\n").unwrap();
+        let mut app = app();
+        app.session.swatch_libraries.set_user_dir(Some(dir.to_string_lossy().to_string()));
+        let panel = panel_of(app.run("window.swatchLibrary", json!({"library": "user/Gone.gpl"})).unwrap());
+        tidy(&mut app);
+        assert!(is_open(&app.ui, &panel));
+        std::fs::remove_file(dir.join("Gone.gpl")).unwrap();
+        app.session.swatch_libraries.rescan();
+        tidy(&mut app);
+        assert!(!is_open(&app.ui, &panel));
+        let _ = std::fs::remove_dir_all(dir);
+    }
+
+    #[test]
+    fn the_panel_menu_has_persistent() {
+        let mut app = app();
+        let panel = panel_of(app.run("window.swatchLibrary", json!({"library": "pastels"})).unwrap());
+        let text = crate::tests_labels::painted_text(&mut app, |app, ui| menu(app, ui, &panel));
+        for item in ["Add to Swatches", "Small List View", "Show Find Field", "Previous Library", "Persistent", "Close Library"] {
+            assert!(text.contains(item), "{item}: {text}");
+        }
+    }
 }
diff --git a/crates/ui-egui/src/panels/mod.rs b/crates/ui-egui/src/panels/mod.rs
index b996134e6..5f534dc05 100644
--- a/crates/ui-egui/src/panels/mod.rs
+++ b/crates/ui-egui/src/panels/mod.rs
@@ -178,6 +178,7 @@ pub fn show_icon_panel(app: &mut VectorcraftApp, ui: &mut Ui, id: &str) {
         links::ID => links::show(app, ui),
         asset_export::ID => asset_export::show(app, ui),
         css_properties::ID => css_properties::show(app, ui),
+        id if library_panel::parse(id).is_some() => library_panel::show(app, ui, id),
         _ => {
             dim_label(ui, tl!("This panel is on the roadmap (see the parity plan)."));
         }
@@ -228,6 +229,7 @@ pub fn panel_menu_items(app: &mut VectorcraftApp, ui: &mut Ui, id: &str) -> bool
         css_properties::ID => css_properties::menu(app, ui),
         variables::ID => variables::menu(app, ui),
         "actions" => actions::menu(app, ui),
+        id if library_panel::parse(id).is_some() => library_panel::menu(app, ui, id),
         _ => return false,
     }
     true
diff --git a/crates/ui-egui/src/panels/swatches.rs b/crates/ui-egui/src/panels/swatches.rs
index e45af6b40..33ac5b4b1 100644
--- a/crates/ui-egui/src/panels/swatches.rs
+++ b/crates/ui-egui/src/panels/swatches.rs
@@ -22,8 +22,9 @@ use crate::theme::Tokens;
 use crate::widgets::{self, PanelDrag, SwatchRows, menu_item, swatch_tile};
 use crate::{VectorcraftApp, icons};
 
-/// View modes of the swatch list (and of the library panel).
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+/// View modes of the swatch list (and of the library panels: `ui.libraryPanel {view}`).
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+#[serde(rename_all = "camelCase")]
 pub enum View {
     SmallThumb,
     #[default]
@@ -927,7 +928,7 @@ fn delete(app: &mut VectorcraftApp, names: Vec<String>, now: bool) {
 fn bottom(app: &mut VectorcraftApp, ui: &mut Ui, sel: &[String]) {
     let kind: Kind = pstate(ui.ctx(), "swatch-kind");
     widgets::bottom_bar(ui, |ui| {
-        let open = app.ui.library_panel.as_ref().is_some_and(|o| o.kind == SwatchLibraries::KIND);
+        let open = library_panel::any_open::<SwatchLibraries>(&app.ui);
         let lr = widgets::icon_button(ui, "library", SwatchLibraries::MENU, open, 24.0);
         egui::Popup::menu(&lr).show(|ui| {
             ui.set_min_width(200.0);
@@ -1107,12 +1108,14 @@ pub(crate) fn limit_key(app: &VectorcraftApp, l: &str) -> Result<String, String>
     swatchlib::library(&app.session, l).map(|(info, _)| info.id).ok_or_else(|| format!("no swatch library `{l}` (see swatch.library.list)"))
 }
 
-/// Swatch libraries in the library panel (engine: `swatch.library.*`).
+/// Swatch libraries in library panels (engine: `swatch.library.*`).
 pub(crate) struct SwatchLibraries;
 
 impl LibraryKind for SwatchLibraries {
     const KIND: &'static str = "swatches";
     const OPEN: &'static str = "window.swatchLibrary";
+    const LIST: &'static str = "swatch.library.list";
+    const LOAD: &'static str = "swatch.library.load";
     const MENU: &'static str = "Swatch Libraries Menu";
     const ADD: &'static str = "Add to Swatches";
     type Lib = Arc<SwatchLibrary>;
@@ -1124,6 +1127,12 @@ impl LibraryKind for SwatchLibraries {
     fn get(app: &VectorcraftApp, id: &str) -> Option<(String, Self::Lib)> {
         swatchlib::library(&app.session, id).map(|(info, lib)| (info.name, lib))
     }
+    fn find(app: &VectorcraftApp, key: &str) -> Option<(String, String, usize)> {
+        swatchlib::library(&app.session, key).map(|(info, lib)| (info.id, info.name, lib.len()))
+    }
+    fn path(app: &VectorcraftApp, id: &str) -> Option<String> {
+        app.session.swatch_libraries.path(id).map(str::to_string)
+    }
     /// Ungrouped swatches, then each colour group's folder and swatches (a group whose name
     /// matches shows all of them), as in the Swatches panel.
     fn rows<'a>(lib: &'a Self::Lib, query: &str) -> Vec<Row<'a, Swatch>> {
@@ -1189,15 +1198,13 @@ fn add_from_library(app: &mut VectorcraftApp, params: Value) {
     }
 }
 
-/// `window.swatchLibrary {library}`: open a swatch library in the library panel (`library` null
-/// closes it).
+/// `window.swatchLibrary {library}`: open a swatch library in its own panel (`library` null closes
+/// every swatch library panel).
 pub(crate) fn open_library(app: &mut VectorcraftApp, p: &Value) -> Result<Value, String> {
-    library_panel::open_command::<SwatchLibraries>(app, p, "swatch.library.list", |app, key| {
-        swatchlib::library(&app.session, key).map(|(info, lib)| (info.id, info.name, lib.len()))
-    })
+    library_panel::open_command::<SwatchLibraries>(app, p)
 }
 
-/// `swatch.library.load` params, then open the library in the panel.
+/// `swatch.library.load` params, then open the library in its panel.
 pub(crate) fn load_library(app: &mut VectorcraftApp, params: Value) -> Result<Value, String> {
     let r = app.run("swatch.library.load", params)?;
     open_library(app, &json!({ "library": r["library"] }))
diff --git a/crates/ui-egui/src/panels/tests_style_libraries.rs b/crates/ui-egui/src/panels/tests_style_libraries.rs
index 31165c03e..a77681938 100644
--- a/crates/ui-egui/src/panels/tests_style_libraries.rs
+++ b/crates/ui-egui/src/panels/tests_style_libraries.rs
@@ -8,7 +8,7 @@ use vectorcraft_doc::style_libs::STYLE_LIBRARIES;
 use vectorcraft_engine::Session;
 
 use super::graphic_styles::GraphicStyleLibraries;
-use super::library_panel::{self, LibraryKind, OpenLibrary};
+use super::library_panel::{self, LibraryKind, LibraryPanel, last_open};
 use crate::VectorcraftApp;
 
 fn app_with(services: crate::Services) -> VectorcraftApp {
@@ -52,7 +52,7 @@ fn click(app: &mut VectorcraftApp, ctx: &egui::Context, name: &str, modifiers: M
     for t in [time, time + 0.25] {
         frame(ctx, vec![], Modifiers::NONE, t, |ui| library_panel::show_window(app, ui.ctx()));
     }
-    let id = library_panel::tile_id::<GraphicStyleLibraries>(name);
+    let id = library_panel::tile_id(&last_open(&app.ui).map(LibraryPanel::panel).unwrap_or_default(), name);
     let at = ctx.read_response(id).unwrap_or_else(|| panic!("no tile for {name}")).rect.center();
     let button = |pressed| Event::PointerButton { pos: at, button: PointerButton::Primary, pressed, modifiers };
     frame(ctx, vec![Event::PointerMoved(at), button(true), button(false)], modifiers, time + 0.5, |ui| library_panel::show_window(app, ui.ctx()));
@@ -69,13 +69,13 @@ fn clicking_a_library_style_adds_and_applies_it_in_one_step() {
     let rect = app.run("shape.rectangle", json!({"x": 10, "y": 10, "width": 80, "height": 40})).unwrap()["id"].as_u64().unwrap();
     let r = app.run("window.graphicStyleLibrary", json!({"library": "Shadows and Glows"})).unwrap();
     assert_eq!((r["open"].as_str(), r["name"].as_str()), (Some("shadows-glows"), Some("Shadows and Glows")));
-    assert_eq!(app.ui.library_panel, Some(OpenLibrary { kind: "graphicStyles".into(), id: "shadows-glows".into() }));
+    assert_eq!(last_open(&app.ui).map(|p| (p.kind.as_str(), p.id.as_str())), Some(("graphicStyles", "shadows-glows")));
     let undo = undo_len(&app);
     click(&mut app, &ctx, "Halo", Modifiers::NONE, 0.0);
     let (g, linked) = app.session.selection_graphic_style().expect("applied to the selection");
     assert_eq!((g.name.as_str(), linked), ("Halo", true));
     assert_eq!(undo_len(&app), undo + 1, "added and applied as one undo step");
-    let tile = ctx.read_response(library_panel::tile_id::<GraphicStyleLibraries>("Halo")).unwrap().rect;
+    let tile = ctx.read_response(library_panel::tile_id("library:graphicStyles:shadows-glows", "Halo")).unwrap().rect;
     assert_eq!(tile.width(), 30.0, "styles open in large thumbnails");
     // Alt-click adds the style's appearance on top, unlinked.
     let fills = |app: &VectorcraftApp| app.session.doc().unwrap().doc.node(vectorcraft_doc::NodeId(rect)).unwrap().appearance.items.len();
@@ -98,7 +98,7 @@ fn clicking_a_library_style_adds_and_applies_it_in_one_step() {
     assert!(std::sync::Arc::ptr_eq(&lib, &GraphicStyleLibraries::get(&app, "shadows-glows").unwrap().1));
     assert!(app.run("window.graphicStyleLibrary", json!({"library": "nope"})).is_err());
     app.run("window.graphicStyleLibrary", json!({"library": null})).unwrap();
-    assert!(app.ui.library_panel.is_none());
+    assert!(last_open(&app.ui).is_none());
 }
 
 #[test]
@@ -153,7 +153,7 @@ fn save_dialog_writes_user_libraries_that_the_window_menu_lists() {
     assert!(app.ui.dialog.is_none());
     assert_eq!(user_items(&app), [("Warm".to_string(), "window.userGraphicStyleLibrary1".to_string())]);
     app.run("window.userGraphicStyleLibrary1", json!({})).unwrap();
-    assert_eq!(app.ui.library_panel.as_ref().map(|o| o.id.as_str()), Some("user/Warm.vcstyles"));
+    assert_eq!(last_open(&app.ui).map(|p| p.id.as_str()), Some("user/Warm.vcstyles"));
     let (name, lib) = GraphicStyleLibraries::get(&app, "user/Warm.vcstyles").unwrap();
     assert_eq!((name.as_str(), lib.len()), ("Warm", 1), "only the selected style");
     let _ = std::fs::remove_dir_all(dir);
@@ -179,7 +179,7 @@ fn saving_to_a_file_and_opening_a_vcstyles_file() {
     assert!(path.ends_with(".vcstyles"), "{path}");
     // Opening it opens it in the library panel, not as a document.
     crate::io::open_bytes(&mut app, "Saved.vcstyles", &bytes, None).unwrap();
-    let open = app.ui.library_panel.clone().unwrap();
+    let open = last_open(&app.ui).cloned().unwrap();
     assert_eq!(open.kind, GraphicStyleLibraries::KIND);
     assert_eq!(app.session.documents().len(), 1);
     let other = GraphicStyleLibraries::list(&app).into_iter().find(|l| l.id == open.id).unwrap();
diff --git a/crates/ui-egui/src/state.rs b/crates/ui-egui/src/state.rs
index 86d98c3c9..3e825ee91 100644
--- a/crates/ui-egui/src/state.rs
+++ b/crates/ui-egui/src/state.rs
@@ -394,9 +394,11 @@ pub struct UiState {
     /// Color Guide panel: variation kind, steps and amount (Color Guide Options).
     #[serde(default)]
     pub color_guide: vectorcraft_color::harmony::GuideOptions,
-    /// The library open in the library panel (Window → Swatch Libraries).
+    /// The library panels' settings (Window → Swatch Libraries, Graphic Style Libraries): of each
+    /// library opened, and of the persistent ones, which reopen at startup, also once closed
+    /// ([`crate::panels::library_panel`], `ui.libraryPanel`).
     #[serde(default)]
-    pub library_panel: Option<crate::panels::library_panel::OpenLibrary>,
+    pub library_panels: Vec<crate::panels::library_panel::LibraryPanel>,
     /// Flattener Preview panel: highlight, overprints, preset and options (`ui.flattenerPreview`).
     #[serde(default)]
     pub flattener_preview: crate::panels::flattener_preview::Settings,
@@ -642,7 +644,7 @@ impl FloatingPanels {
     pub fn sanitize(groups: &mut Vec<FloatingPanels>, toolbar_pos: &mut Option<[f32; 2]>) {
         let mut seen = std::collections::BTreeSet::new();
         groups.retain_mut(|g| {
-            g.panels.retain(|id| all_panels().any(|(p, _)| p == id) && seen.insert(id.clone()));
+            g.panels.retain(|id| crate::menus::normalize_panel(id) == Some(id.as_str()) && seen.insert(id.clone()));
             g.active = g.active.min(g.panels.len().saturating_sub(1));
             !g.panels.is_empty()
         });
@@ -769,7 +771,7 @@ impl Default for UiState {
             favorite_fonts: vec![],
             engine_prefs: Value::Null,
             color_guide: Default::default(),
-            library_panel: None,
+            library_panels: vec![],
             flattener_preview: Default::default(),
             color_guide_limit: String::new(),
             align_to: Default::default(),
diff --git a/crates/ui-egui/src/tests_paintchips.rs b/crates/ui-egui/src/tests_paintchips.rs
index b28ad83e3..8845000e9 100644
--- a/crates/ui-egui/src/tests_paintchips.rs
+++ b/crates/ui-egui/src/tests_paintchips.rs
@@ -319,6 +319,6 @@ fn the_popover_swatch_libraries_button_opens_the_libraries_menu() {
     let earth = menu_item_rect(&shapes, "Earth Tones").expect("the menu lists the built-in libraries");
     assert!(earth.top() > defaults.top());
     click(&mut app, &ctx, earth.center(), Modifiers::NONE, control_bar);
-    let open = app.ui.library_panel.as_ref().map(|o| (o.kind.clone(), o.id.clone()));
+    let open = crate::panels::library_panel::last_open(&app.ui).map(|o| (o.kind.clone(), o.id.clone()));
     assert_eq!(open, Some(("swatches".into(), "earth-tones".into())));
 }
diff --git a/crates/ui-egui/src/tests_picks.rs b/crates/ui-egui/src/tests_picks.rs
index da9da921a..2c071fa2f 100644
--- a/crates/ui-egui/src/tests_picks.rs
+++ b/crates/ui-egui/src/tests_picks.rs
@@ -12,7 +12,7 @@ use serde_json::{Value, json};
 use vectorcraft_engine::Session;
 
 use crate::panels::graphic_styles::GraphicStyleLibraries;
-use crate::panels::library_panel::library_menu;
+use crate::panels::library_panel::{self, library_menu};
 use crate::panels::swatches::SwatchLibraries;
 use crate::picks::{self, PickRequest};
 use crate::state::Dialog;
@@ -232,10 +232,10 @@ fn other_swatch_library_asks_off_the_ui_thread() {
     click(&mut app, "Other Library…", library_menu::<SwatchLibraries>);
     assert!(matches!(shown.requests().as_slice(), [PickRequest::Open(_)]));
     poll(&mut app);
-    assert!(app.ui.library_panel.is_none() && app.ui.status.is_empty(), "{}", app.ui.status);
+    assert!(library_panel::last_open(&app.ui).is_none() && app.ui.status.is_empty(), "{}", app.ui.status);
     shown.answer(&[&file]);
     poll(&mut app);
-    let open = app.ui.library_panel.clone().unwrap_or_else(|| panic!("no library open: {}", app.ui.status));
+    let open = library_panel::last_open(&app.ui).cloned().unwrap_or_else(|| panic!("no library open: {}", app.ui.status));
     assert_eq!(open.kind, "swatches");
     let (_, lib) = vectorcraft_engine::cmd::swatchlib::library(&app.session, &open.id).unwrap();
     assert!(lib.swatch("Signal").is_some(), "{}", open.id);
@@ -255,7 +255,7 @@ fn other_graphic_style_library_asks_off_the_ui_thread() {
     assert!(matches!(shown.requests().as_slice(), [PickRequest::Open(_)]));
     shown.answer(&[&file]);
     poll(&mut app);
-    let open = app.ui.library_panel.clone().unwrap_or_else(|| panic!("no library open: {}", app.ui.status));
+    let open = library_panel::last_open(&app.ui).cloned().unwrap_or_else(|| panic!("no library open: {}", app.ui.status));
     assert_eq!(open.kind, "graphicStyles");
     let (_, lib) = vectorcraft_engine::cmd::stylelib::library(&app.session, &open.id).unwrap();
     assert!(lib.style("Poster Look").is_some(), "{}", open.id);
diff --git a/crates/ui-egui/src/tests_place.rs b/crates/ui-egui/src/tests_place.rs
index 381d08817..3f35e81e6 100644
--- a/crates/ui-egui/src/tests_place.rs
+++ b/crates/ui-egui/src/tests_place.rs
@@ -168,7 +168,7 @@ fn a_dropped_swatch_library_opens_in_the_library_panel() {
     let gpl = temp_file("dropped.gpl", b"GIMP Palette\nName: Dropped\n#\n255   0   0\tRed\n  0 128 255\tSky\n");
     frame(&mut app, &ctx, vec![], &[&gpl], false);
     let id = format!("loaded/{gpl}");
-    assert_eq!(app.ui.library_panel.as_ref().map(|o| o.id.as_str()), Some(id.as_str()), "{}", app.ui.status);
+    assert_eq!(crate::panels::library_panel::last_open(&app.ui).map(|o| o.id.as_str()), Some(id.as_str()), "{}", app.ui.status);
     let lib = app.session.execute("swatch.library.get", &json!({"library": id})).unwrap();
     let names: Vec<&str> = lib["swatches"].as_array().unwrap().iter().filter_map(|w| w["name"].as_str()).collect();
     assert_eq!((lib["name"].as_str(), names), (Some("Dropped"), vec!["Red", "Sky"]));
diff --git a/docs/mcp.md b/docs/mcp.md
index 1feeaaa8f..cde63dac5 100644
--- a/docs/mcp.md
+++ b/docs/mcp.md
@@ -1399,6 +1399,34 @@ with); without `path` it returns `{data}`, and `user: true` saves into the user
 file, or another document's graphic styles, as a library to add from; a file in the user library folder, or a file
 with the same extension and bytes as one there, loads as that User Defined library.
 
+## Library panels
+
+Each swatch or graphic style library opens in a read-only panel of its own (#2603), as in Illustrator, and
+several can be open at once. `window.swatchLibrary {library}` and `window.graphicStyleLibrary {library}`
+(remote mode, `invoke_menu`) open one floating, or bring its panel forward when it is already open, and answer
+`{open, panel, name, count}`; `library: null` closes every panel of that kind. The panel id is
+`library:<kind>:<library id>` (`library:swatches:pastels`, `library:graphicStyles:hand-drawn`,
+`library:swatches:loaded/C:/Palettes/Brand.ase`), and the panel commands take it like any other panel's:
+`window.panel.float {panel, onto?, x?, y?}` groups or moves it, `window.panel.dock {panel}` docks it,
+`window.panel.close {panel}` closes it. `window.swatchLibrary.other {path}` and `window.graphicStyleLibrary.other
+{path}` load a file and open it the same way.
+
+`ui.libraryPanel {panel, library?, view?, showFind?, persistent?}` sets one panel: `library` shows another library
+of its kind in that panel (what Previous Library and Next Library do; a library open in a panel of its own is
+brought forward instead), `view` is `smallThumb`, `mediumThumb`, `largeThumb`, `smallList` or `largeList`,
+`showFind` shows or hides the find field, and `persistent: true` is the panel menu's Persistent: the panel
+reopens when the app starts, with its view and find field, where the saved layout had it (or floating). A
+library loaded from a file is read again from its path; one whose file is gone is left out, and the status bar
+says which. A closed persistent panel can still be set, so `persistent: false` stops it reopening. The reply
+is `{panel, kind, library, view, showFind, persistent, open}`, and `ui.inspect` lists every panel's settings
+under `ui.library_panels`.
+
+```json
+{"name":"invoke_menu","arguments":{"command":"window.swatchLibrary","params":{"library":"pastels"}}}
+{"name":"invoke_menu","arguments":{"command":"ui.libraryPanel","params":{"panel":"library:swatches:pastels","view":"smallList","persistent":true}}}
+{"name":"invoke_menu","arguments":{"command":"window.panel.close","params":{"panel":"library:swatches:pastels"}}}
+```
+
 ## Libraries
 
 The Libraries panel's libraries hold graphics, colours and character and paragraph styles that any document can use.
diff --git a/docs/ui-parity.md b/docs/ui-parity.md
index 4de19cebb..d97382388 100644
--- a/docs/ui-parity.md
+++ b/docs/ui-parity.md
@@ -1,6 +1,6 @@
 # UI and interaction parity
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-17 · **Change:** minor (the Selection tool threads text from the out port, #2572 in part; scores unchanged; Group Selection picks and moves one path of a compound path, #2441 in part; the Move dialog opens on the last move and its last checkboxes; scores unchanged; transparency grid visibility saved in native documents, #1968; Live Corners radius up to the neighbouring cuts, #2332; Image Trace quick presets: wording corrected to the shipped behaviour, the Image Trace button opens the controls; batch exporting, #1935; document window scroll bars, #2322; Anchor Point tool: a click on a handle end retracts that handle only, #2267; scores unchanged; Smart Guides: the dragged end of a straight segment keeps to its extension at any angle, #2120; Warp Options controls verified by focused checks and original-image review; estimates unchanged; existing-guide Escape cancellation validated 2026-10-14; scores and hours unchanged; open-path anchor Delete keeps surviving runs separate; estimates unchanged; Artboard tab-switch follow-up historically validated on `a0671777`; scores and hours unchanged; Artboard clean active-tab close/Delete follow-up validated 2026-10-15; Curvature curve geometry, #1236 in part; Width-point finite-arithmetic follow-up validated; scores and hours unchanged; Image Trace adjustment discovery; later 2026-10-14 merges: macOS save sheet Format menu back to missing, #1855, #866 reopened; anchor X/Y/W/H in the Transform panel, Properties and Control bar, #1824; Snap to Grid over Snap to Pixel, #1816; toolbar labels, columns and the All Tools drawer, #1751; Actions panel selection, #1629 in part; scores unchanged; 2026-10-14 merges: anchor Align and Distribute, #1636; Delete on closed paths and whole objects, #1674; selection inside isolation, #1666; Escape in a Direct Selection drag and while typing, #1743, #1686; Pen clicks under 3 px, #1663; [ and ] on more tools, #1661 in part; fields commit on click away, #1787; command search keys, #1757; a guide's position in the Transform panel is a convenience with no parity claim, #1659; scores unchanged; intersect Smart Guides for drawn points and dragged anchors, #1602 in part; a ruler guide's position in the Transform panel, #1597 in part; Symbol Options before New Symbol, #1560; tool flyout widths, #1616; Pathfinder Trim, Merge and Crop strokes, #1570; scores unchanged; G1/M11: Artboard deletion and history selection normalization; history regressions and full workspace CI pass; scores and hours unchanged; Width Point Edit: Shift-double-click enables adjoining adjustment; plain double-click keeps it off; scores and hours unchanged; per-corner radius fields with a link toggle, split from #1594; Join merges anchors lying on one another, #1533; correction: Average and Join with a corner or smooth choice is missing, not done; guide objects take the guide colour and style and Lock Guides, #1534; Keyboard Shortcuts lists commands outside the menus, #1539; round corners next to curves and the Smooth tool's reach, #1512; Make Compound Path on a group, #1537; dialog slider rails, #1483; template layers stay in Preview in Outline view, #1486; Direct Selection takes the selected object's anchor where anchors coincide, #1508; Tabs panel stop drags, #1458; Split Into Grid dialog, #1462; Transform Objects and Reflect's angle, #1448 and #1460; Pathfinder panel on a group, #1450; value fields: readable selection, #1465 in part, and a focused field follows its value, #1457; scores unchanged; Transform dialogs have a live Preview and step with the arrow keys, #1412; transform tools, dialogs and Move act on direct-selected anchors, #1408; the bounding box hides during a corner drag, #1229; scores unchanged; dialogs focus their first field on every open, #1367, and a first field that starts greyed out once it is enabled, #1395; scores unchanged; Rectangular Grid and Polar Grid click dialogs take the skew, frame, compound path and Fill Grid options, #1377 in part, score unchanged; Live Corners: a Direct Selection click on a widget selects its corner, #1239; custom ruler origin, #1212; Artboard tool clicks fit the topmost editable object in one undo step (#1227); scores unchanged; Pathfinder single-result source names and SVG IDs retained, #1293; DXF control-point SPLINE closure read, #1299 follow-up; Document Setup: Edit Artboards closes the modal after applying valid settings; pointer-click regressions; scores and hours unchanged; Artboards: Escape exits editing; an active drag cancels first; shortcut-routing regression; scores and hours unchanged; Simplify preview/counts and valid rewritten-path selection (#1272); parity remains partial; Texture-effect drag redraws optimized (#1257); idle Windows interaction still unverified; scores unchanged; Curvature point display improved (#1236, in part); scores unchanged; Direct Selection: no-op anchor Align preserves Undo, Redo and saved state (#1180 follow-up); Eyedropper cursor distinguished from precise crosshair (#1269); scores unchanged; Eyedropper can read visible locked and outside-isolation sources (#1251); scores unchanged; Direct Selection: independent segment picks and Delete (#1278); scores unchanged; Adding paint to an unpainted zero-width stroke restores the 1 pt default (#1253); scores unchanged; macOS save sheets offer a Format menu, #866; Attributes fill-rule controls edit the compound when a member is selected, #1197; a marquee needs to touch a path, not just lie inside its fill, #1103; earlier: Live Corners round corners between curved sides, #1144) · **Target:** Adobe Illustrator 2026 (30.x)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-17 · **Change:** minor (library panels: one per library, dockable and tabbable, with Persistent, #2603; the Selection tool threads text from the out port, #2572 in part; scores unchanged; Group Selection picks and moves one path of a compound path, #2441 in part; the Move dialog opens on the last move and its last checkboxes; scores unchanged; transparency grid visibility saved in native documents, #1968; Live Corners radius up to the neighbouring cuts, #2332; Image Trace quick presets: wording corrected to the shipped behaviour, the Image Trace button opens the controls; batch exporting, #1935; document window scroll bars, #2322; Anchor Point tool: a click on a handle end retracts that handle only, #2267; scores unchanged; Smart Guides: the dragged end of a straight segment keeps to its extension at any angle, #2120; Warp Options controls verified by focused checks and original-image review; estimates unchanged; existing-guide Escape cancellation validated 2026-10-14; scores and hours unchanged; open-path anchor Delete keeps surviving runs separate; estimates unchanged; Artboard tab-switch follow-up historically validated on `a0671777`; scores and hours unchanged; Artboard clean active-tab close/Delete follow-up validated 2026-10-15; Curvature curve geometry, #1236 in part; Width-point finite-arithmetic follow-up validated; scores and hours unchanged; Image Trace adjustment discovery; later 2026-10-14 merges: macOS save sheet Format menu back to missing, #1855, #866 reopened; anchor X/Y/W/H in the Transform panel, Properties and Control bar, #1824; Snap to Grid over Snap to Pixel, #1816; toolbar labels, columns and the All Tools drawer, #1751; Actions panel selection, #1629 in part; scores unchanged; 2026-10-14 merges: anchor Align and Distribute, #1636; Delete on closed paths and whole objects, #1674; selection inside isolation, #1666; Escape in a Direct Selection drag and while typing, #1743, #1686; Pen clicks under 3 px, #1663; [ and ] on more tools, #1661 in part; fields commit on click away, #1787; command search keys, #1757; a guide's position in the Transform panel is a convenience with no parity claim, #1659; scores unchanged; intersect Smart Guides for drawn points and dragged anchors, #1602 in part; a ruler guide's position in the Transform panel, #1597 in part; Symbol Options before New Symbol, #1560; tool flyout widths, #1616; Pathfinder Trim, Merge and Crop strokes, #1570; scores unchanged; G1/M11: Artboard deletion and history selection normalization; history regressions and full workspace CI pass; scores and hours unchanged; Width Point Edit: Shift-double-click enables adjoining adjustment; plain double-click keeps it off; scores and hours unchanged; per-corner radius fields with a link toggle, split from #1594; Join merges anchors lying on one another, #1533; correction: Average and Join with a corner or smooth choice is missing, not done; guide objects take the guide colour and style and Lock Guides, #1534; Keyboard Shortcuts lists commands outside the menus, #1539; round corners next to curves and the Smooth tool's reach, #1512; Make Compound Path on a group, #1537; dialog slider rails, #1483; template layers stay in Preview in Outline view, #1486; Direct Selection takes the selected object's anchor where anchors coincide, #1508; Tabs panel stop drags, #1458; Split Into Grid dialog, #1462; Transform Objects and Reflect's angle, #1448 and #1460; Pathfinder panel on a group, #1450; value fields: readable selection, #1465 in part, and a focused field follows its value, #1457; scores unchanged; Transform dialogs have a live Preview and step with the arrow keys, #1412; transform tools, dialogs and Move act on direct-selected anchors, #1408; the bounding box hides during a corner drag, #1229; scores unchanged; dialogs focus their first field on every open, #1367, and a first field that starts greyed out once it is enabled, #1395; scores unchanged; Rectangular Grid and Polar Grid click dialogs take the skew, frame, compound path and Fill Grid options, #1377 in part, score unchanged; Live Corners: a Direct Selection click on a widget selects its corner, #1239; custom ruler origin, #1212; Artboard tool clicks fit the topmost editable object in one undo step (#1227); scores unchanged; Pathfinder single-result source names and SVG IDs retained, #1293; DXF control-point SPLINE closure read, #1299 follow-up; Document Setup: Edit Artboards closes the modal after applying valid settings; pointer-click regressions; scores and hours unchanged; Artboards: Escape exits editing; an active drag cancels first; shortcut-routing regression; scores and hours unchanged; Simplify preview/counts and valid rewritten-path selection (#1272); parity remains partial; Texture-effect drag redraws optimized (#1257); idle Windows interaction still unverified; scores unchanged; Curvature point display improved (#1236, in part); scores unchanged; Direct Selection: no-op anchor Align preserves Undo, Redo and saved state (#1180 follow-up); Eyedropper cursor distinguished from precise crosshair (#1269); scores unchanged; Eyedropper can read visible locked and outside-isolation sources (#1251); scores unchanged; Direct Selection: independent segment picks and Delete (#1278); scores unchanged; Adding paint to an unpainted zero-width stroke restores the 1 pt default (#1253); scores unchanged; macOS save sheets offer a Format menu, #866; Attributes fill-rule controls edit the compound when a member is selected, #1197; a marquee needs to touch a path, not just lie inside its fill, #1103; earlier: Live Corners round corners between curved sides, #1144) · **Target:** Adobe Illustrator 2026 (30.x)
 
 How VectorCraft's tools, handles, snapping and panels behave next to Illustrator's. A vector illustrator's
 trust is in the details: where a handle lands, what Shift and Alt do mid-drag, what a smart guide snaps to,
@@ -223,6 +223,7 @@ panel-menu commands such as Break Link to Symbol), so they can be given shortcut
 | Blend panel (30.7) | partial | Window › Blend: Make, Spacing, Orientation, Reverse Front to Back, Reverse Spine, Replace Spine, Expand and Release, running the Object › Blend commands; the easing and color controls are missing |
 | SVG Interactivity, Retype, Comments, Version History panels | missing | the last two are cloud features (out of scope) |
 | Workspaces (save, reset, switch) | done | |
+| Swatch and graphic style library panels: each library opens in a panel of its own, several at once, that floats, groups, docks and closes like any panel; opening an open library brings its panel forward; Previous / Next Library change the library in place; the panel menu's Persistent reopens the panel at startup with its view and find field (a library loaded from a file is read again, a missing file is skipped with a status-bar note) | done | #2603; panel ids `library:<kind>:<id>`, `ui.libraryPanel {panel, library?, view?, showFind?, persistent?}`; the library panels have no sort option, as before |
 | DXF export/import preserves intended curve closure | done | #1299; R13–2018 closed SPLINE bit set/read; an open curve ending at its start stays open; knots and control points unchanged; native CIRCLE/ARC export and CNC preset remain pending |
 | macOS save sheet: choose the format from a menu | done | #866; the save panel is VectorCraft's own `NSSavePanel` with its Format menu set before the sheet opens (`apps/vectorcraft/src/mac_save_format.rs`); #1855 had withdrawn the menu that was added after the sheet began, which made Save As, Save a Copy and the first Save show no sheet |
 | Preferences: every option acts | partial | ~16 stored but unused (#394) |
@@ -242,6 +243,7 @@ re-measure of the panels added since. Slider rails show on Medium Dark (#1808, #
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-17 | minor | Library panels (#2603): each swatch or graphic style library opens in its own dockable, tabbable panel, several at once; the panel menu's Persistent reopens a panel at startup with its view and find field, a library loaded from a file read again from its path; scores unchanged (estimated) |
 | 2026-10-17 | minor | Selection tool: clicking the red out port of overflowing area type, then a closed path, empty canvas or a dragged rectangle threads the text there (#2572 in part); Escape cancels. Scores and hours unchanged. |
 | 2026-10-17 | minor | Group Selection picks one path of a compound path (the outer shape or a hole) and moves it on its own; a second click adds the compound path (#2441, in part) |
 | 2026-10-16 | minor | The Move dialog opens on the offset of the last drag or Move and with the checkboxes it was last confirmed with; scores unchanged |