diff --git a/crates/doc/src/appearance/tests.rs b/crates/doc/src/appearance/tests.rs
index 5225c7152..3e3d610f4 100644
--- a/crates/doc/src/appearance/tests.rs
+++ b/crates/doc/src/appearance/tests.rs
@@ -326,11 +326,8 @@ fn mixed_appearances_share_their_equal_rows() {
     assert_eq!(shared.items, vec![vec![1, 1]], "the stroke, not the fills");
     assert_eq!(shared.effects, vec![vec![0, 0]]);
     // The stroke under an extra fill in the second object.
-    let c = Appearance {
-        items: vec![fill(Color::BLACK), fill(Color::WHITE), stroke.clone()],
-        effects: vec![feather.clone()],
-        ..Appearance::default()
-    };
+    let c =
+        Appearance { items: vec![fill(Color::BLACK), fill(Color::WHITE), stroke.clone()], effects: vec![feather.clone()], ..Appearance::default() };
     let shared = SharedStack::of(&[&a, &c]);
     assert_eq!(shared.items, vec![vec![1, 2]]);
     assert_eq!(shared.item_in(1, 1), Some(2));
diff --git a/crates/engine/src/cmd/appearance.rs b/crates/engine/src/cmd/appearance.rs
index 8c1678ec9..3e1173d8b 100644
--- a/crates/engine/src/cmd/appearance.rs
+++ b/crates/engine/src/cmd/appearance.rs
@@ -313,12 +313,13 @@ pub(crate) fn appearances_differ(d: &vectorcraft_doc::Document, ids: &[NodeId])
     aps.any(|a| a != first)
 }
 
-/// Indices `idx` of the first target's items (aligned with `aligned`) in each of `ids`: where
-/// each target has the item equal to the first's (see [`SharedStack`]), else the same indices.
-/// A target missing one of them gets only those it has.
+/// Indices `idx` of the first target's items (aligned with `aligned`) in each of `ids`: the first
+/// target's own, and in each other one the items equal to them there (see [`SharedStack`]), each
+/// index on its own: one the targets don't share is left out of the others (never taken as the
+/// same index there). Not aligned, or one target: the same indices in each.
 pub(crate) fn items_per_target(d: &vectorcraft_doc::Document, ids: &[NodeId], idx: &[usize], aligned: bool) -> Vec<Vec<usize>> {
-    match shared_stack(d, ids).filter(|sh| aligned && idx.iter().all(|i| sh.has_item(*i))) {
-        Some(sh) => (0..ids.len()).map(|k| idx.iter().filter_map(|i| sh.item_in(*i, k)).collect()).collect(),
+    match shared_stack(d, ids).filter(|_| aligned) {
+        Some(sh) => (0..ids.len()).map(|k| if k == 0 { idx.to_vec() } else { idx.iter().filter_map(|i| sh.item_in(*i, k)).collect() }).collect(),
         None => vec![idx.to_vec(); ids.len()],
     }
 }
diff --git a/crates/engine/src/tests/appearance.rs b/crates/engine/src/tests/appearance.rs
index 0530b3d28..d6336b86d 100644
--- a/crates/engine/src/tests/appearance.rs
+++ b/crates/engine/src/tests/appearance.rs
@@ -585,3 +585,16 @@ fn shared_effects_and_new_fills_reach_every_selected_object() {
     // Rows of different stacks aren't reordered together.
     assert!(s.execute("appearance.moveItem", &json!({"from": 1, "to": 0, "aligned": true})).is_err());
 }
+
+/// Rows deleted together, one shared (the stroke) and one not (a's fill): each object loses its
+/// own copy of the shared row, and the other object keeps the items at those indices of a's stack.
+#[test]
+fn removing_shared_and_unshared_rows_removes_only_the_shared_ones_elsewhere() {
+    let mut s = session();
+    let (a, b) = mixed_circles(&mut s, true);
+    // b is [Fill, Fill, Stroke]; a's rows 0 (its fill) and 1 (the shared stroke).
+    let fills_b: Vec<_> = node(&s, b).appearance.items.iter().take(2).cloned().collect();
+    run(&mut s, "appearance.removeItem", json!({"indices": [0, 1], "aligned": true}));
+    assert!(node(&s, a).appearance.items.is_empty(), "a loses both");
+    assert_eq!(node(&s, b).appearance.items, fills_b, "b loses only its stroke, keeping both fills");
+}
diff --git a/crates/ui-egui/src/dialogs/effect.rs b/crates/ui-egui/src/dialogs/effect.rs
index 4bc5bde5b..b668f0791 100644
--- a/crates/ui-egui/src/dialogs/effect.rs
+++ b/crates/ui-egui/src/dialogs/effect.rs
@@ -74,6 +74,10 @@ pub fn open(app: &mut VectorcraftApp, p: &Value) -> Result<Value, String> {
     if let Some(item) = p.get("item") {
         fields.insert("__item".into(), item.clone());
     }
+    // A shared row of a mixed selection: OK edits each object's own copy of the effect.
+    if p.get("aligned").and_then(Value::as_bool) == Some(true) {
+        fields.insert("__aligned".into(), json!(true));
+    }
     match p.get("index").and_then(Value::as_u64) {
         Some(k) => {
             let e = applied.get(k as usize).ok_or_else(|| format!("no effect at index {k}"))?;
@@ -737,6 +741,9 @@ fn command(d: &Dialog) -> (&'static str, Value) {
         if super::warp_effect::is_warp(&id) && d.bool("__warp_style_changed") {
             p["warpStyle"] = json!(id.strip_prefix("warp."));
         }
+        if d.bool("__aligned") {
+            p["aligned"] = json!(true);
+        }
         return ("effect.setParams", p);
     }
     let mut p = json!({"effect": d.str("__effect"), "params": params});
@@ -766,6 +773,27 @@ fn confirm(app: &mut VectorcraftApp, d: &Dialog) -> Result<Value, String> {
 mod tests {
     use super::*;
 
+    /// An applied effect's dialog opened on a shared row of a mixed selection (`aligned`) edits
+    /// each object's own copy on OK; opened otherwise it edits the index as given.
+    #[test]
+    fn a_shared_rows_dialog_edits_each_objects_copy() {
+        let dialog = |aligned: bool| {
+            let mut fields = Map::new();
+            fields.insert("__effect".into(), json!("stylize.feather"));
+            fields.insert("__index".into(), json!(0));
+            fields.insert("__item".into(), Value::Null);
+            fields.insert("radius".into(), json!(8));
+            if aligned {
+                fields.insert("__aligned".into(), json!(true));
+            }
+            Dialog { kind: "effect".into(), fields }
+        };
+        let (cmd, p) = command(&dialog(true));
+        assert_eq!((cmd, &p["aligned"], &p["params"]["radius"]), ("effect.setParams", &json!(true), &json!(8)));
+        assert!(p["params"].get("__aligned").is_none());
+        assert!(command(&dialog(false)).1.get("aligned").is_none());
+    }
+
     #[test]
     fn fields_that_pick_a_value_are_dropdowns_of_its_values() {
         // The values come from the effect's parameter documentation (`joins: "miter"|"round"|…`).
diff --git a/crates/ui-egui/src/menus/ui_commands.rs b/crates/ui-egui/src/menus/ui_commands.rs
index 9867228b5..63b60e2b5 100644
--- a/crates/ui-egui/src/menus/ui_commands.rs
+++ b/crates/ui-egui/src/menus/ui_commands.rs
@@ -506,7 +506,7 @@ pub const UI_COMMANDS: &[(&str, &str, &str, &str)] = &[
         "effect.dialog",
         "Effect…",
         "",
-        "{effect: id, index?: int (edit that applied effect in place, prefilled; OK runs effect.setParams), item?: appearance item index|null (the fill/stroke whose effects, null the object's; default: the Appearance panel's active item)} open the effect's dialog with live preview; without `index`, an effect already in that list first opens `effectExists` (confirm edits it, discard adds another) → {pending: \"effectExists\"}",
+        "{effect: id, index?: int (edit that applied effect in place, prefilled; OK runs effect.setParams), item?: appearance item index|null (the fill/stroke whose effects, null the object's; default: the Appearance panel's active item), aligned?: bool (index and item are rows of the first selected object's stack, which OK edits in each object where it has them, as effect.setParams does)} open the effect's dialog with live preview; without `index`, an effect already in that list first opens `effectExists` (confirm edits it, discard adds another) → {pending: \"effectExists\"}",
     ),
     ("ui.paramDialog", "Command Dialog", "", "{command, label?, params} open a parameter dialog for any command"),
     (
diff --git a/crates/ui-egui/src/panels/appearance.rs b/crates/ui-egui/src/panels/appearance.rs
index bc760c5ac..b1337be67 100644
--- a/crates/ui-egui/src/panels/appearance.rs
+++ b/crates/ui-egui/src/panels/appearance.rs
@@ -774,7 +774,7 @@ fn effect_row(app: &mut VectorcraftApp, ui: &mut Ui, item: Option<usize>, k: usi
     if link(ui, pos2(lx, r.center().y), ("ap-fx-link", item, k), &shown_effect_label(&e.id)) {
         select_row(app, ui.ctx(), this);
         if has_options(&e.id) {
-            app.run("effect.dialog", json!({"effect": e.id, "index": k, "item": item})).ok();
+            app.run("effect.dialog", aligned(app, json!({"effect": e.id, "index": k, "item": item}))).ok();
         } else {
             set_pstate(ui.ctx(), &open_key, !open);
         }
@@ -916,7 +916,7 @@ fn effect_editor(app: &mut VectorcraftApp, ui: &mut Ui, item: Option<usize>, k:
         app.run("effect.setParams", aligned(app, json!({"item": item, "index": k, "params": {key: v}}))).ok();
     }
     if edit {
-        app.run("effect.dialog", json!({"effect": e.id, "index": k, "item": item})).ok();
+        app.run("effect.dialog", aligned(app, json!({"effect": e.id, "index": k, "item": item}))).ok();
     }
 }