diff --git a/crates/doc/src/appearance.rs b/crates/doc/src/appearance.rs
index 2dc6cbabb..4ac758ffa 100644
--- a/crates/doc/src/appearance.rs
+++ b/crates/doc/src/appearance.rs
@@ -506,5 +506,105 @@ impl Appearance {
     }
 }
 
+/// The most fills, strokes or effects a stack may have to be matched against another's
+/// ([`align`]); a larger stack shares nothing with the others.
+const MAX_ALIGNED: usize = 1024;
+
+/// Where each entry of `first` is in `other`: the entries equal in both (`same`), matched in their
+/// stacking order (a longest common subsequence, so the matches never cross), by index into
+/// `other`; `None` where `other` has no equal entry left for it.
+pub fn align<T>(first: &[T], other: &[T], same: impl Fn(&T, &T) -> bool) -> Vec<Option<usize>> {
+    let (n, m) = (first.len(), other.len());
+    let mut out = vec![None; n];
+    if n == 0 || m == 0 || n > MAX_ALIGNED || m > MAX_ALIGNED {
+        return out;
+    }
+    // `len[i][j]`: the longest match of `first[i..]` and `other[j..]`.
+    let w = m + 1;
+    let mut len = vec![0u16; (n + 1) * w];
+    for i in (0..n).rev() {
+        for j in (0..m).rev() {
+            let here = match (first.get(i), other.get(j)) {
+                (Some(a), Some(b)) if same(a, b) => len.get((i + 1) * w + j + 1).copied().unwrap_or(0).saturating_add(1),
+                _ => len.get((i + 1) * w + j).copied().unwrap_or(0).max(len.get(i * w + j + 1).copied().unwrap_or(0)),
+            };
+            if let Some(c) = len.get_mut(i * w + j) {
+                *c = here;
+            }
+        }
+    }
+    let (mut i, mut j) = (0, 0);
+    while i < n && j < m {
+        let at = |a: usize, b: usize| len.get(a * w + b).copied().unwrap_or(0);
+        match (first.get(i), other.get(j)) {
+            (Some(a), Some(b)) if same(a, b) && at(i, j) == at(i + 1, j + 1).saturating_add(1) => {
+                if let Some(o) = out.get_mut(i) {
+                    *o = Some(j);
+                }
+                i += 1;
+                j += 1;
+            }
+            _ if at(i + 1, j) >= at(i, j + 1) => i += 1,
+            _ => j += 1,
+        }
+    }
+    out
+}
+
+/// What several objects' appearances share, as the Appearance panel lists a mixed selection: the
+/// fills and strokes, and the object-level effects, that every one of them has an equal copy of, in
+/// stacking order ([`align`]), each with where it is in every object's own stack.
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct SharedStack {
+    /// Each shared fill or stroke, in the first object's paint order: its index in each object's
+    /// `items` (the first object's first).
+    pub items: Vec<Vec<usize>>,
+    /// Each shared object-level effect: its index in each object's `effects`.
+    pub effects: Vec<Vec<usize>>,
+}
+
+impl SharedStack {
+    /// The rows `appearances` share (see [`SharedStack`]). One appearance shares all of itself.
+    pub fn of(appearances: &[&Appearance]) -> Self {
+        let Some((first, rest)) = appearances.split_first() else { return Self::default() };
+        fn shared<T>(first: &[T], rest: Vec<&[T]>, same: impl Fn(&T, &T) -> bool + Copy) -> Vec<Vec<usize>> {
+            let maps: Vec<Vec<Option<usize>>> = rest.iter().map(|o| align(first, o, same)).collect();
+            (0..first.len())
+                .filter_map(|i| {
+                    let mut at = vec![i];
+                    for m in &maps {
+                        at.push((*m.get(i)?)?);
+                    }
+                    Some(at)
+                })
+                .collect()
+        }
+        Self {
+            items: shared(&first.items, rest.iter().map(|a| a.items.as_slice()).collect(), |a, b| a == b),
+            effects: shared(&first.effects, rest.iter().map(|a| a.effects.as_slice()).collect(), |a, b| a == b),
+        }
+    }
+
+    /// Where the first object's fill or stroke `first` is in object `k`'s stack, when it is shared.
+    pub fn item_in(&self, first: usize, k: usize) -> Option<usize> {
+        self.items.iter().find(|at| at.first() == Some(&first))?.get(k).copied()
+    }
+
+    /// Where the first object's object-level effect `first` is in object `k`'s effects, when shared.
+    pub fn effect_in(&self, first: usize, k: usize) -> Option<usize> {
+        self.effects.iter().find(|at| at.first() == Some(&first))?.get(k).copied()
+    }
+
+    /// Is the first object's fill or stroke `i` shared?
+    pub fn has_item(&self, i: usize) -> bool {
+        self.items.iter().any(|at| at.first() == Some(&i))
+    }
+
+    /// Is the first object's object-level effect `k` shared?
+    pub fn has_effect(&self, k: usize) -> bool {
+        self.effects.iter().any(|at| at.first() == Some(&k))
+    }
+}
+
 #[cfg(test)]
 mod tests;
diff --git a/crates/doc/src/appearance/tests.rs b/crates/doc/src/appearance/tests.rs
index 49d2f4e77..3e3d610f4 100644
--- a/crates/doc/src/appearance/tests.rs
+++ b/crates/doc/src/appearance/tests.rs
@@ -311,3 +311,39 @@ fn contents_slot_follows_item_edits_and_round_trips() {
     assert_eq!(old.contents_index, None);
     assert!(!serde_json::to_string(&Appearance::default_art()).unwrap().contains("contents_index"));
 }
+
+/// The issue's case (#4174): two circles with different fills, the same stroke and the same
+/// effect share the stroke and the effect, not the fills; a shared stroke at another place in one
+/// stack maps to its own index there; nothing shared shares nothing; equal stacks share all.
+#[test]
+fn mixed_appearances_share_their_equal_rows() {
+    let stroke = AppearanceItem::Stroke(StrokeLayer::new(Paint::solid(Color::rgb(0.0, 0.0, 1.0)), 11.0));
+    let fill = |c: Color| AppearanceItem::Fill(FillLayer::new(Paint::solid(c)));
+    let feather = Effect { id: "stylize.feather".into(), params: serde_json::json!({"radius": 5}), visible: true };
+    let a = Appearance { items: vec![fill(Color::rgb(1.0, 1.0, 0.0)), stroke.clone()], effects: vec![feather.clone()], ..Appearance::default() };
+    let b = Appearance { items: vec![fill(Color::rgb(1.0, 0.0, 0.0)), stroke.clone()], effects: vec![feather.clone()], ..Appearance::default() };
+    let shared = SharedStack::of(&[&a, &b]);
+    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 shared = SharedStack::of(&[&a, &c]);
+    assert_eq!(shared.items, vec![vec![1, 2]]);
+    assert_eq!(shared.item_in(1, 1), Some(2));
+    assert_eq!(shared.item_in(0, 1), None);
+    // Nothing alike.
+    let d = Appearance { items: vec![fill(Color::WHITE)], ..Appearance::default() };
+    let none = SharedStack::of(&[&a, &d]);
+    assert!(none.items.is_empty() && none.effects.is_empty());
+    // Equal stacks share everything, each row where it is.
+    assert_eq!(SharedStack::of(&[&a, &a.clone(), &a.clone()]).items, vec![vec![0, 0, 0], vec![1, 1, 1]]);
+}
+
+/// Matches keep their stacking order: two equal rows in the opposite order match once.
+#[test]
+fn aligned_rows_never_cross() {
+    assert_eq!(align(&[1, 2], &[2, 1], |a, b| a == b).iter().filter(|m| m.is_some()).count(), 1);
+    assert_eq!(align(&[1, 2, 3], &[9, 1, 3], |a, b| a == b), vec![Some(1), None, Some(2)]);
+    assert_eq!(align::<i32>(&[], &[1], |a, b| a == b), Vec::<Option<usize>>::new());
+}
diff --git a/crates/engine/src/cmd/appearance.rs b/crates/engine/src/cmd/appearance.rs
index 6fdced122..3e1173d8b 100644
--- a/crates/engine/src/cmd/appearance.rs
+++ b/crates/engine/src/cmd/appearance.rs
@@ -21,6 +21,7 @@
 
 use serde_json::{Value, json};
 use vectorcraft_color::{BlendMode, Paint};
+use vectorcraft_doc::appearance::SharedStack;
 use vectorcraft_doc::{Appearance, AppearanceItem, CharStyle, FillLayer, Node, NodeKind, ParaStyle, StrokeLayer};
 use vectorcraft_geom::Rect;
 
@@ -74,7 +75,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Appearance Item",
             [],
             None,
-            "{index: paint-order item index, ids?|id? (default: the selection), target?: \"object\"|\"contents\", opacity?: 0..100, blend?: name, visible?: bool, weight?: pt (strokes), color?|none?|swatch?|gradient? (as paint.setFill), tint?: 0..100, keepModel?: bool (both as paint.setFill)} edit one fill/stroke of each target object's own appearance stack",
+            "{index: paint-order item index, ids?|id? (default: the selection), target?: \"object\"|\"contents\", opacity?: 0..100, blend?: name, visible?: bool, weight?: pt (strokes), color?|none?|swatch?|gradient? (as paint.setFill), tint?: 0..100, keepModel?: bool (both as paint.setFill), aligned?: bool (index and item are rows of the first target's stack: each other target edits its equal one, as the Appearance panel does for a mixed selection)} edit one fill/stroke of each target object's own appearance stack",
             has_doc,
             set_item
         ),
@@ -83,7 +84,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Remove Item",
             [],
             None,
-            "{index | indices: [..] (paint-order item indices), ids?|id?, target?} remove those fills/strokes from each target object's own stack",
+            "{index | indices: [..] (paint-order item indices), ids?|id?, target?, aligned?: bool (index and item are rows of the first target's stack: each other target edits its equal one, as the Appearance panel does for a mixed selection)} remove those fills/strokes from each target object's own stack",
             has_doc,
             remove_item
         ),
@@ -101,7 +102,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Duplicate Item",
             ["Window", "Appearance"],
             None,
-            "{index | indices: [..] (paint-order item indices), to?: paint-order index of the copy (one `index` only; default: right above it, as Alt-dragging a row places it), ids?|id?, target?} copy fills/strokes with their effects",
+            "{index | indices: [..] (paint-order item indices), to?: paint-order index of the copy (one `index` only; default: right above it, as Alt-dragging a row places it; not with aligned rows of a mixed selection), ids?|id?, target?, aligned?: bool (index and item are rows of the first target's stack: each other target edits its equal one, as the Appearance panel does for a mixed selection)} copy fills/strokes with their effects",
             has_doc,
             duplicate_item
         ),
@@ -110,7 +111,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Reorder Appearance Item",
             [],
             None,
-            "{from: paint-order item index | \"contents\", to, contents?: count, ids?|id?, target?} move fill/stroke `from` to paint-order index `to`; on a group, layer or type the Contents (Characters) row stays between the same items (a moved item landing next to it keeps its side) unless `contents` says how many items paint below it afterwards. from \"contents\": move that row so `to` items paint below the members (characters) and the rest above → {index: where the item landed | contents: the row's slot}",
+            "{from: paint-order item index | \"contents\", to, contents?: count, ids?|id?, target?, aligned?: bool (refused when the targets' appearances differ)} move fill/stroke `from` to paint-order index `to`; on a group, layer or type the Contents (Characters) row stays between the same items (a moved item landing next to it keeps its side) unless `contents` says how many items paint below it afterwards. from \"contents\": move that row so `to` items paint below the members (characters) and the rest above → {index: where the item landed | contents: the row's slot}",
             has_doc,
             move_item
         ),
@@ -203,8 +204,11 @@ pub(crate) enum ItemTarget {
     /// The topmost fill or stroke (for effects: the object-level effects).
     Top,
     /// Item `index`. `explicit`: named by the `item` param, so it must exist and be of the edited
-    /// kind; otherwise it is the panel's active item, which applies only where it fits.
-    Item { index: usize, explicit: bool },
+    /// kind; otherwise it is the panel's active item, which applies only where it fits. `aligned`:
+    /// `index` is a row of the first target's stack, and each other target edits the item equal to
+    /// it there ([`ItemTarget::per_target`]): the active item always is (it is a row of the first
+    /// selected object's stack), an explicit one with `aligned: true`.
+    Item { index: usize, explicit: bool, aligned: bool },
 }
 
 /// Parse the `item` param of `cmd` (see the module docs).
@@ -218,11 +222,11 @@ pub(crate) fn item_target_at(s: &Session, p: &Value, key: &str, cmd: &str) -> Re
         Some(Value::Null) => Ok(ItemTarget::Top),
         Some(v) => v
             .as_u64()
-            .map(|i| ItemTarget::Item { index: index(i), explicit: true })
+            .map(|i| ItemTarget::Item { index: index(i), explicit: true, aligned: aligned(p) })
             .ok_or_else(|| bad(cmd, format!("`{key}` must be an appearance item index (paint order) or null"))),
         // The active item is a row of the first selected object's own stack.
         None if p.get("ids").is_some() || p.get("id").is_some() || targets_contents(p)? => Ok(ItemTarget::Top),
-        None => Ok(s.appearance_item().map_or(ItemTarget::Top, |index| ItemTarget::Item { index, explicit: false })),
+        None => Ok(s.appearance_item().map_or(ItemTarget::Top, |index| ItemTarget::Item { index, explicit: false, aligned: true })),
     }
 }
 
@@ -240,17 +244,30 @@ impl ItemTarget {
     /// of its own kind, so a fill row leaves stroke edits on the topmost stroke of the painted
     /// leaves (as without an active item) and vice versa. Explicit items are kept (and checked).
     pub(crate) fn of_kind(self, s: &Session, fill: bool) -> Self {
-        let ItemTarget::Item { index, explicit: false } = self else { return self };
+        let ItemTarget::Item { index, explicit: false, .. } = self else { return self };
         let fits =
             s.active().and_then(|st| st.doc.node(*st.selection.subjects().first()?)?.appearance.items.get(index).map(|it| it.is_fill() == fill));
         if fits == Some(true) { self } else { ItemTarget::Top }
     }
 
+    /// This target for each of `ids` in `d` (in their order): an aligned item (a row of the first
+    /// target's stack) is, in each other target, the item equal to it there (see
+    /// [`SharedStack`]); `None` for a target that has none, which the edit leaves alone. A row the
+    /// targets don't share, and any other target, stands for itself in every target.
+    pub(crate) fn per_target(self, d: &vectorcraft_doc::Document, ids: &[NodeId]) -> Vec<Option<ItemTarget>> {
+        let ItemTarget::Item { index, explicit, aligned: true } = self else { return vec![Some(self); ids.len()] };
+        let Some(shared) = shared_stack(d, ids) else { return vec![Some(self); ids.len()] };
+        if !shared.has_item(index) {
+            return vec![Some(self); ids.len()];
+        }
+        (0..ids.len()).map(|k| shared.item_in(index, k).map(|index| ItemTarget::Item { index, explicit, aligned: true })).collect()
+    }
+
     /// The item of `ap` a fill (`fill`) or stroke edit changes; `None` = the topmost one.
     pub(crate) fn resolve(self, ap: &Appearance, fill: bool, cmd: &str) -> Result<Option<usize>> {
         match self {
             ItemTarget::Top => Ok(None),
-            ItemTarget::Item { index, explicit } => match ap.item_of_kind(Some(index), fill) {
+            ItemTarget::Item { index, explicit, .. } => match ap.item_of_kind(Some(index), fill) {
                 None if explicit => Err(bad(
                     cmd,
                     match ap.items.get(index) {
@@ -268,12 +285,45 @@ impl ItemTarget {
         match self {
             ItemTarget::Top => Ok(None),
             ItemTarget::Item { index, .. } if index < ap.items.len() => Ok(Some(index)),
-            ItemTarget::Item { index, explicit: true } => Err(bad(cmd, format!("no appearance item {index}"))),
+            ItemTarget::Item { index, explicit: true, .. } => Err(bad(cmd, format!("no appearance item {index}"))),
             ItemTarget::Item { explicit: false, .. } => Ok(None),
         }
     }
 }
 
+/// Does `p` say its item and effect indices are rows of the first target's stack (`aligned`),
+/// which each other target edits where it has them (see [`ItemTarget::per_target`])?
+pub(crate) fn aligned(p: &Value) -> bool {
+    p.get("aligned").and_then(Value::as_bool).unwrap_or(false)
+}
+
+/// What the appearances of `ids` share, when there are several of them and they all exist.
+pub(crate) fn shared_stack(d: &vectorcraft_doc::Document, ids: &[NodeId]) -> Option<SharedStack> {
+    if ids.len() < 2 {
+        return None;
+    }
+    let aps: Vec<&Appearance> = ids.iter().map(|id| d.node(*id).map(|n| &*n.appearance)).collect::<Option<_>>()?;
+    Some(SharedStack::of(&aps))
+}
+
+/// Do the appearances of `ids` differ (several objects whose stacks aren't all equal)?
+pub(crate) fn appearances_differ(d: &vectorcraft_doc::Document, ids: &[NodeId]) -> bool {
+    let mut aps = ids.iter().filter_map(|id| d.node(*id)).map(|n| &n.appearance);
+    let Some(first) = aps.next() else { return false };
+    aps.any(|a| a != first)
+}
+
+/// 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(|_| 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()],
+    }
+}
+
 /// Whether the `target` param asks for the contents of groups and layers (see the module docs).
 fn targets_contents(p: &Value) -> Result<bool> {
     match p.get("target") {
@@ -352,9 +402,11 @@ pub(crate) fn edit_items_then(
         return Ok(());
     }
     let before = s.doc()?.doc.clone();
+    let per = item.per_target(&before, ids);
     super::overprint::edit_counted(s, label, |d| {
         let mut edited = Vec::new();
-        for id in ids {
+        for (id, item) in ids.iter().zip(&per) {
+            let Some(item) = item else { continue };
             let Some(n) = d.node_mut(*id) else { continue };
             let index = item.resolve(&n.appearance, fill, cmd)?;
             f(n, index)?;
@@ -562,8 +614,10 @@ fn set_item(s: &mut Session, p: &Value) -> Result<Value> {
     // When every object comes out as it was (for example, when none has item `index`), the document
     // and its undo history stay as they are.
     let before = s.doc()?.doc.clone();
+    let per = items_per_target(&before, &ids, &[idx], aligned(p));
     super::overprint::edit_counted(s, "Appearance", |d| {
-        for id in &ids {
+        for (id, at) in ids.iter().zip(&per) {
+            let Some(&idx) = at.first() else { continue };
             let Some(n) = d.node_mut(*id) else { continue };
             if p.get("weight").is_none()
                 && let Some(pa) = &paint
@@ -625,9 +679,12 @@ fn remove_item(s: &mut Session, p: &Value) -> Result<Value> {
     // When no object has an item at any of the indices, the document and its undo history stay as
     // they are.
     let before = s.doc()?.doc.clone();
+    let per = items_per_target(&before, &ids, &idx, aligned(p));
     super::overprint::edit_counted(s, "Remove Item", |d| {
-        for id in &ids {
+        for (id, idx) in ids.iter().zip(&per) {
             if let Some(n) = d.node_mut(*id) {
+                let mut idx = idx.clone();
+                idx.sort_unstable();
                 // From the top down, so the lower indices stay valid.
                 for &i in idx.iter().rev() {
                     n.appearance.remove_item(i);
@@ -650,11 +707,18 @@ fn duplicate_item(s: &mut Session, p: &Value) -> Result<Value> {
     let ids = require_targets(s, p, C)?;
     // Where the first object's copy landed (the active item lives in the first object's stack).
     let mut first_at = None;
+    // Aligned rows of a mixed selection are copied right above themselves in each object.
+    if aligned(p) && to.is_some() && shared_stack(&s.doc()?.doc, &ids).is_some() {
+        return Err(bad(C, "`to` takes the rows of one object's stack, not aligned rows"));
+    }
+    let per = items_per_target(&s.doc()?.doc, &ids, &idx, aligned(p));
     s.edit("Duplicate Item", |d, _| {
         let mut any = false;
-        for id in &ids {
+        for (id, idx) in ids.iter().zip(&per) {
             let Some(n) = d.node_mut(*id) else { continue };
             let ap = &mut n.appearance;
+            let mut idx = idx.clone();
+            idx.sort_unstable();
             // From the top down, so the lower indices stay valid.
             for &i in idx.iter().rev() {
                 if let Some(item) = ap.items.get(i).cloned() {
@@ -697,6 +761,10 @@ fn move_item(s: &mut Session, p: &Value) -> Result<Value> {
         return move_contents(s, &ids, to);
     }
     let from = index_param(p, "from", C)?;
+    // Where an aligned row would go in each of several different stacks isn't one place.
+    if aligned(p) && appearances_differ(&s.doc()?.doc, &ids) {
+        return Err(bad(C, "rows of objects whose appearances differ can't be reordered together"));
+    }
     let contents = p.get("contents").map(|_| index_param(p, "contents", C)).transpose()?;
     let mut landed = to;
     // When every object's stack comes out as it was, the document and its undo history stay as they
diff --git a/crates/engine/src/cmd/effectcmd.rs b/crates/engine/src/cmd/effectcmd.rs
index de6776586..e91a621c4 100644
--- a/crates/engine/src/cmd/effectcmd.rs
+++ b/crates/engine/src/cmd/effectcmd.rs
@@ -12,7 +12,7 @@ use vectorcraft_doc::{Document, Effect, Node, NodeKind, StrokeLayer};
 use vectorcraft_geom::{FillRule, PathData};
 use vectorcraft_render::effects;
 
-use super::appearance::{ItemTarget, appearance_targets, index_param, item_target, item_target_at};
+use super::appearance::{ItemTarget, aligned, appearance_targets, index_param, item_target, item_target_at, shared_stack};
 use super::expand::has_seeded;
 use super::rasterfx;
 use super::*;
@@ -42,7 +42,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Remove Effect",
             [],
             None,
-            "{index: int (position in the effect list), item?: appearance item index|null (that fill/stroke's effects; omitted: the active item, else the object's), ids?|id?: [..], target?: \"object\"|\"contents\"} → {ids}",
+            "{index: int (position in the effect list), item?: appearance item index|null (that fill/stroke's effects; omitted: the active item, else the object's), ids?|id?: [..], target?: \"object\"|\"contents\", aligned?: bool (index and item are rows of the first target's stack: each other target edits its equal one, as the Appearance panel does for a mixed selection)} → {ids}",
             has_doc,
             remove
         ),
@@ -51,7 +51,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Effect Options",
             [],
             None,
-            "{index: int, params?: {…} (merged into the current parameters), warpStyle?: string (an existing Warp style suffix, e.g. arc or flag; changes only an applied Warp in place), visible?: bool, item?: appearance item index|null (as effect.remove), ids?|id?: [..], target?: \"object\"|\"contents\"} → {ids}",
+            "{index: int, params?: {…} (merged into the current parameters), warpStyle?: string (an existing Warp style suffix, e.g. arc or flag; changes only an applied Warp in place), visible?: bool, item?: appearance item index|null (as effect.remove), ids?|id?: [..], target?: \"object\"|\"contents\", aligned?: bool (index and item are rows of the first target's stack: each other target edits its equal one, as the Appearance panel does for a mixed selection)} → {ids}",
             has_doc,
             set_params
         ),
@@ -60,7 +60,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "3D Lighting Preset",
             [],
             None,
-            "{index: int, preset: standard|diffuse|topLeft|right, item?: appearance item index|null (omitted: the active item, else the object's), ids?|id?: [..], target?: object|contents} replace an applied 3D effect's light rig and ambient with an original lighting preset; preserve shading, geometry and view; all targets must have a 3D effect at index; one undo step → {ids}",
+            "{index: int, preset: standard|diffuse|topLeft|right, item?: appearance item index|null (omitted: the active item, else the object's), ids?|id?: [..], target?: object|contents, aligned?: bool (index and item are rows of the first target's stack: each other target edits its equal one, as the Appearance panel does for a mixed selection)} replace an applied 3D effect's light rig and ambient with an original lighting preset; preserve shading, geometry and view; all targets must have a 3D effect at index; one undo step → {ids}",
             has_doc,
             lighting_preset
         ),
@@ -78,7 +78,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Duplicate Effect",
             [],
             None,
-            "{index: int, item?: appearance item index|null (as effect.remove), ids?|id?: [..], target?: \"object\"|\"contents\"} insert a copy of the effect right after it → {ids}",
+            "{index: int, item?: appearance item index|null (as effect.remove), ids?|id?: [..], target?: \"object\"|\"contents\", aligned?: bool (index and item are rows of the first target's stack: each other target edits its equal one, as the Appearance panel does for a mixed selection)} insert a copy of the effect right after it → {ids}",
             has_doc,
             duplicate
         ),
@@ -87,7 +87,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Move Effect",
             [],
             None,
-            "{from: int (position in the source list), to: int (its position in the destination list afterwards), fromItem?: appearance item index|null (the source list: that fill/stroke's effects, null the object's; omitted: the active item, else the object's), toItem?: item index|null (the destination list; default: the source list), copy?: bool (copy instead of move, as Alt-dragging the row), ids?|id?: [..], target?: \"object\"|\"contents\"} reorder an effect or move it between the object and its fills/strokes, as one undo step → {ids, index, item}",
+            "{from: int (position in the source list), to: int (its position in the destination list afterwards), fromItem?: appearance item index|null (the source list: that fill/stroke's effects, null the object's; omitted: the active item, else the object's), toItem?: item index|null (the destination list; default: the source list), copy?: bool (copy instead of move, as Alt-dragging the row), ids?|id?: [..], target?: \"object\"|\"contents\", aligned?: bool (refused when the targets' appearances differ)} reorder an effect or move it between the object and its fills/strokes, as one undo step → {ids, index, item}",
             has_doc,
             move_effect
         ),
@@ -101,6 +101,35 @@ fn ids_json(ids: &[NodeId]) -> Value {
 /// One undo step (`label`) running `f` on the effect list `item` addresses on each target (an
 /// appearance item's own effects, or the object's). Errors with `none` when `f` changed no object;
 /// returns the changed ids.
+/// Each target of an effect edit aimed at `item` and effect `index`: the object, the item whose
+/// effects it edits (`None`: the object's own) and the effect's index there. With `aligned` (see
+/// [`ItemTarget::per_target`]) `item` and `index` are the first target's, and each other target
+/// edits its equal item, or its equal object-level effect; a target without them is left out.
+pub(crate) fn effect_targets(s: &Session, p: &Value, item: ItemTarget, index: usize, cmd: &str) -> Result<Vec<(NodeId, Option<usize>, usize)>> {
+    let roots = appearance_targets(s, p)?;
+    let d = &s.doc()?.doc;
+    let per = item.per_target(d, &roots);
+    let shared = if aligned(p) { shared_stack(d, &roots) } else { None };
+    let mut out = Vec::with_capacity(roots.len());
+    for (k, (id, item)) in roots.iter().zip(per).enumerate() {
+        let (Some(item), Some(n)) = (item, d.node(*id)) else { continue };
+        let at = item.effects_item(&n.appearance, cmd)?;
+        // An object-level effect the targets share is, in each, where it is there.
+        let first = roots.first().and_then(|f| d.node(*f));
+        let first_level = first.map(|f| item.effects_item(&f.appearance, cmd)).transpose()?.flatten();
+        let index = match (&shared, at, first_level) {
+            (Some(sh), None, None) if sh.has_effect(index) => match sh.effect_in(index, k) {
+                Some(i) => i,
+                None => continue,
+            },
+            _ => index,
+        };
+        out.push((*id, at, index));
+    }
+    Ok(out)
+}
+
+#[allow(clippy::too_many_arguments)]
 fn edit_effects(
     s: &mut Session,
     p: &Value,
@@ -108,17 +137,17 @@ fn edit_effects(
     cmd: &str,
     label: &str,
     none: &str,
-    mut f: impl FnMut(&mut Vec<Effect>) -> bool,
+    index: usize,
+    mut f: impl FnMut(&mut Vec<Effect>, usize) -> bool,
 ) -> Result<Vec<NodeId>> {
-    let roots = appearance_targets(s, p)?;
+    let targets = effect_targets(s, p, item, index, cmd)?;
     s.edit(label, |d, _| {
         let mut done = vec![];
-        for id in &roots {
-            let Some(n) = d.node_mut(*id) else { continue };
-            let index = item.effects_item(&n.appearance, cmd)?;
-            if n.appearance.effects_mut(index).is_some_and(&mut f) {
+        for &(id, at, index) in &targets {
+            let Some(n) = d.node_mut(id) else { continue };
+            if n.appearance.effects_mut(at).is_some_and(|fx| f(fx, index)) {
                 check_revolve_count(n, cmd)?;
-                done.push(*id);
+                done.push(id);
             }
         }
         if done.is_empty() {
@@ -185,7 +214,7 @@ pub(crate) fn apply(s: &mut Session, p: &Value) -> Result<Value> {
         }
     }
     let mut index = 0;
-    let ids = edit_effects(s, p, item, C, &label, "Apply Effect: select objects", |fx| {
+    let ids = edit_effects(s, p, item, C, &label, "Apply Effect: select objects", 0, |fx, _| {
         fx.push(effect.clone());
         index = fx.len() - 1;
         true
@@ -241,7 +270,7 @@ fn remove(s: &mut Session, p: &Value) -> Result<Value> {
     const C: &str = "effect.remove";
     let index = index_param(p, "index", C)?;
     let item = item_target(s, p, C)?;
-    let ids = edit_effects(s, p, item, C, "Remove Effect", &format!("{C}: no effect at index {index}"), |fx| {
+    let ids = edit_effects(s, p, item, C, "Remove Effect", &format!("{C}: no effect at index {index}"), index, |fx, index| {
         (index < fx.len()).then(|| fx.remove(index)).is_some()
     })?;
     Ok(json!({ "ids": ids_json(&ids) }))
@@ -251,12 +280,14 @@ fn duplicate(s: &mut Session, p: &Value) -> Result<Value> {
     const C: &str = "effect.duplicate";
     let index = index_param(p, "index", C)?;
     let item = item_target(s, p, C)?;
-    let ids = edit_effects(s, p, item, C, "Duplicate Effect", &format!("{C}: no effect at index {index}"), |fx| match fx.get(index).cloned() {
-        Some(e) => {
-            fx.insert(index + 1, e);
-            true
+    let ids = edit_effects(s, p, item, C, "Duplicate Effect", &format!("{C}: no effect at index {index}"), index, |fx, index| {
+        match fx.get(index).cloned() {
+            Some(e) => {
+                fx.insert(index + 1, e);
+                true
+            }
+            None => false,
         }
-        None => false,
     })?;
     Ok(json!({ "ids": ids_json(&ids) }))
 }
@@ -269,6 +300,10 @@ fn move_effect(s: &mut Session, p: &Value) -> Result<Value> {
     let dst = if p.get("toItem").is_some() { item_target_at(s, p, "toItem", C)? } else { src };
     let copy = p.get("copy").and_then(Value::as_bool).unwrap_or(false);
     let roots = appearance_targets(s, p)?;
+    // Where an aligned effect would go in each of several different stacks isn't one place.
+    if aligned(p) && super::appearance::appearances_differ(&s.doc()?.doc, &roots) {
+        return Err(bad(C, "effects of objects whose appearances differ can't be moved together"));
+    }
     // Where the effect landed in the first object.
     let mut landed = None;
     let ids = s.edit(if copy { "Duplicate Effect" } else { "Move Effect" }, |d, _| {
@@ -298,14 +333,12 @@ fn move_effect(s: &mut Session, p: &Value) -> Result<Value> {
 /// (none when `p` doesn't say which: running it reports why).
 pub(crate) fn set_params_effects(s: &Session, p: &Value) -> Vec<String> {
     const C: &str = "effect.setParams";
-    let (Ok(index), Ok(item), Ok(ids), Ok(st)) = (index_param(p, "index", C), item_target(s, p, C), appearance_targets(s, p), s.doc()) else {
+    let (Ok(index), Ok(item), Ok(st)) = (index_param(p, "index", C), item_target(s, p, C), s.doc()) else {
         return vec![];
     };
-    let effect = |id: &NodeId| {
-        let ap = &st.doc.node(*id)?.appearance;
-        Some(ap.effects_at(item.effects_item(ap, C).ok()?)?.get(index)?.id.clone())
-    };
-    ids.iter().filter_map(effect).collect()
+    let Ok(targets) = effect_targets(s, p, item, index, C) else { return vec![] };
+    let effect = |&(id, at, index): &(NodeId, Option<usize>, usize)| Some(st.doc.node(id)?.appearance.effects_at(at)?.get(index)?.id.clone());
+    targets.iter().filter_map(effect).collect()
 }
 
 fn lighting_preset(s: &mut Session, p: &Value) -> Result<Value> {
@@ -317,9 +350,8 @@ fn lighting_preset(s: &mut Session, p: &Value) -> Result<Value> {
     let item = item_target(s, p, C)?;
     // Validate the whole selection before changing any object. An unrelated effect or
     // a missing index must not leave just some objects with a new lighting rig.
-    for id in appearance_targets(s, p)? {
+    for (id, slot, index) in effect_targets(s, p, item, index, C)? {
         let n = s.doc()?.doc.node(id).ok_or(EngineError::NoNode(id))?;
-        let slot = item.effects_item(&n.appearance, C)?;
         let effect = n.appearance.effects_at(slot).and_then(|fx| fx.get(index));
         if !effect.is_some_and(|e| effects::is_three_d(&e.id)) {
             return Err(bad(C, format!("object {} needs a 3D effect at index {index}", id.0)));
@@ -359,9 +391,8 @@ fn set_params(s: &mut Session, p: &Value) -> Result<Value> {
     if edited.iter().any(|e| texture_load_effect(e)) {
         load_texture(&mut params, C)?;
     }
-    for id in appearance_targets(s, p)? {
+    for (id, target, index) in effect_targets(s, p, item, index, C)? {
         let n = s.doc()?.doc.node(id).ok_or(EngineError::NoNode(id))?;
-        let target = item.effects_item(&n.appearance, C)?;
         let effect = n.appearance.effects_at(target).and_then(|fx| fx.get(index));
         if warp_id.is_some() && effect.is_some_and(|e| e.id.strip_prefix("warp.").and_then(effects::WarpStyle::from_id).is_none()) {
             return Err(bad(C, "warpStyle can only edit an applied Warp effect"));
@@ -377,7 +408,7 @@ fn set_params(s: &mut Session, p: &Value) -> Result<Value> {
             effects::validate_three_d(n, &e.id, &prospective).map_err(|e| bad(C, e))?;
         }
     }
-    let ids = edit_effects(s, p, item, C, "Effect Options", &format!("{C}: no effect at index {index}"), |fx| {
+    let ids = edit_effects(s, p, item, C, "Effect Options", &format!("{C}: no effect at index {index}"), index, |fx, index| {
         let Some(e) = fx.get_mut(index) else { return false };
         if let Some(id) = &warp_id {
             e.id.clone_from(id);
diff --git a/crates/engine/src/cmd/paint.rs b/crates/engine/src/cmd/paint.rs
index f6e555892..b22d77ac9 100644
--- a/crates/engine/src/cmd/paint.rs
+++ b/crates/engine/src/cmd/paint.rs
@@ -68,7 +68,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Transparency",
             ["Window", "Transparency"],
             None,
-            "{ids?|id?, opacity?: 0..100, blend?: name, isolate?, knockout?: \"on\"|\"off\"|\"neutral\"|bool (true = on, false = neutral), knockoutShape?: bool, item?: appearance item index|null, target?: \"object\"|\"contents\"} for `ids`, the selection, or the object whose opacity mask is being edited; opacity and blend go to the targeted fill/stroke item (omitted: the Appearance panel's active item, else the objects)",
+            "{ids?|id?, opacity?: 0..100, blend?: name, isolate?, knockout?: \"on\"|\"off\"|\"neutral\"|bool (true = on, false = neutral), knockoutShape?: bool, item?: appearance item index|null, target?: \"object\"|\"contents\", aligned?: bool (index and item are rows of the first target's stack: each other target edits its equal one, as the Appearance panel does for a mixed selection)} for `ids`, the selection, or the object whose opacity mask is being edited; opacity and blend go to the targeted fill/stroke item (omitted: the Appearance panel's active item, else the objects)",
             has_doc,
             transparency
         ),
@@ -742,7 +742,7 @@ fn transparency(s: &mut Session, p: &Value) -> Result<Value> {
     q.remove("item");
     q.remove("id");
     q.insert("ids".into(), json!(ids.iter().map(|id| id.0).collect::<Vec<_>>()));
-    let ItemTarget::Item { index, explicit } = item else {
+    let ItemTarget::Item { index, explicit, aligned } = item else {
         return s.execute("object.setProps", &Value::Object(q));
     };
     // Opacity and blend belong to the targeted fill/stroke; isolate/knockout/knockoutShape stay object-level.
@@ -766,7 +766,7 @@ fn transparency(s: &mut Session, p: &Value) -> Result<Value> {
     }
     if opacity.is_some() || blend.is_some() {
         let ids: Vec<u64> = item_ids.iter().map(|id| id.0).collect();
-        s.execute("appearance.setItem", &json!({ "index": index, "ids": ids, "opacity": opacity, "blend": blend }))?;
+        s.execute("appearance.setItem", &json!({ "index": index, "ids": ids, "opacity": opacity, "blend": blend, "aligned": aligned }))?;
     }
     if q.keys().all(|k| k == "ids") {
         return ok();
diff --git a/crates/engine/src/tests/appearance.rs b/crates/engine/src/tests/appearance.rs
index 14d871b58..d6336b86d 100644
--- a/crates/engine/src/tests/appearance.rs
+++ b/crates/engine/src/tests/appearance.rs
@@ -523,3 +523,78 @@ fn clear_and_reduce_keep_a_groups_stack_empty() {
     // The members keep their own appearance.
     assert_eq!(node(&s, a).appearance, members);
 }
+
+/// #4174: two circles with different fills, the same 11 pt blue stroke and the same Feather,
+/// both selected. Their default stacks are `[Fill, Stroke]`; the second gets a second fill under
+/// its stroke when `extra_fill`, so the shared stroke sits at another index there.
+fn mixed_circles(s: &mut Session, extra_fill: bool) -> (NodeId, NodeId) {
+    let mut circle = |x: f64, color: &str| {
+        let id = NodeId(run(s, "shape.ellipse", json!({"x": x, "y": 100, "width": 100, "height": 100}))["id"].as_u64().unwrap());
+        run(s, "paint.setFill", json!({"ids": [id.0], "color": color}));
+        run(s, "appearance.setItem", json!({"ids": [id.0], "index": 1, "color": "#0000ff", "weight": 11}));
+        run(s, "effect.apply", json!({"ids": [id.0], "effect": "stylize.feather", "item": null}));
+        id
+    };
+    let (a, b) = (circle(0.0, "#ffff00"), circle(150.0, "#ff0000"));
+    if extra_fill {
+        // Another fill on top of b's fill and moved under its stroke: [Fill, Fill, Stroke].
+        run(s, "appearance.addFill", json!({"ids": [b.0]}));
+        run(s, "appearance.moveItem", json!({"ids": [b.0], "from": 2, "to": 1}));
+        run(s, "appearance.setItem", json!({"ids": [b.0], "index": 1, "color": "#00ff00"}));
+    }
+    run(s, "select.set", json!({"ids": [a.0, b.0]}));
+    (a, b)
+}
+
+/// The shared stroke row edits the stroke of both circles, whatever its index in each, as one undo
+/// step, leaving their fills alone; undo restores both.
+#[test]
+fn a_shared_row_edits_every_selected_object() {
+    for extra in [false, true] {
+        let mut s = session();
+        let (a, b) = mixed_circles(&mut s, extra);
+        let b_stroke = if extra { 2 } else { 1 };
+        let fills = (node(&s, a).appearance.items.clone(), node(&s, b).appearance.items.clone());
+        let steps = s.doc().unwrap().history.undo.len();
+        // The panel lists the first object's rows: the stroke is a's item 1.
+        run(&mut s, "appearance.setItem", json!({"index": 1, "weight": 4, "aligned": true}));
+        assert_eq!(stroke(&node(&s, a), 1).width, 4.0);
+        assert_eq!(stroke(&node(&s, b), b_stroke).width, 4.0, "extra fill: {extra}");
+        assert_eq!(node(&s, a).appearance.items[0], fills.0[0], "a's fill untouched");
+        assert_eq!(node(&s, b).appearance.items.len(), fills.1.len());
+        assert_eq!(s.doc().unwrap().history.undo.len(), steps + 1, "one undo step");
+        run(&mut s, "edit.undo", json!({}));
+        assert_eq!((node(&s, a).appearance.items.clone(), node(&s, b).appearance.items.clone()), fills, "undo restores both");
+        // The active row (a's item 1) carries paint edits from other panels to both strokes too.
+        run(&mut s, "appearance.setActiveItem", json!({"index": 1}));
+        run(&mut s, "stroke.set", json!({"weight": 7}));
+        assert_eq!(stroke(&node(&s, b), b_stroke).width, 7.0, "extra fill: {extra}");
+    }
+}
+
+/// Removing the shared effect removes it from both; adding a fill adds one to both.
+#[test]
+fn shared_effects_and_new_fills_reach_every_selected_object() {
+    let mut s = session();
+    let (a, b) = mixed_circles(&mut s, true);
+    run(&mut s, "effect.remove", json!({"index": 0, "item": null, "aligned": true}));
+    assert!(node(&s, a).appearance.effects.is_empty() && node(&s, b).appearance.effects.is_empty());
+    let (na, nb) = (node(&s, a).appearance.items.len(), node(&s, b).appearance.items.len());
+    run(&mut s, "appearance.addFill", json!({}));
+    assert_eq!((node(&s, a).appearance.items.len(), node(&s, b).appearance.items.len()), (na + 1, nb + 1));
+    // 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/i18n/bg.tsv b/crates/ui-egui/src/i18n/bg.tsv
index 230e2251c..1f5588aea 100644
--- a/crates/ui-egui/src/i18n/bg.tsv
+++ b/crates/ui-egui/src/i18n/bg.tsv
@@ -1813,6 +1813,7 @@ font-technology	Variable	Променливи
 	Miter Limit:	Ограничение на острите ъгли:
 	Mixed Appearances	Смесени изгледи
 	Mixed Objects	Смесени обекти
+	Mixed	Смесено
 	Mode:	Режим:
 	Model	Модел
 	Modified	Модифицирано
diff --git a/crates/ui-egui/src/i18n/cs.tsv b/crates/ui-egui/src/i18n/cs.tsv
index 07c73f238..ef160b85a 100644
--- a/crates/ui-egui/src/i18n/cs.tsv
+++ b/crates/ui-egui/src/i18n/cs.tsv
@@ -1359,6 +1359,7 @@ lighting	Light	Světlo
 	Hide Thumbnail	Skrýt miniaturu
 	Mixed Appearances	Smíšené vzhledy
 	Mixed Objects	Smíšené objekty
+	Mixed	Smíšené
 	No options	Žádné možnosti
 	No Selection	Nic není vybráno
 	Offset X	Posun X
diff --git a/crates/ui-egui/src/i18n/da.tsv b/crates/ui-egui/src/i18n/da.tsv
index 994f115ab..4e4ca0275 100644
--- a/crates/ui-egui/src/i18n/da.tsv
+++ b/crates/ui-egui/src/i18n/da.tsv
@@ -1276,6 +1276,7 @@ lighting	Light	Lys
 	Hide Thumbnail	Skjul miniatur
 	Mixed Appearances	Blandede udseender
 	Mixed Objects	Blandede objekter
+	Mixed	Blandet
 	No options	Ingen indstillinger
 	No Selection	Ingen markering
 	Offset X	Forskydning X
diff --git a/crates/ui-egui/src/i18n/de.tsv b/crates/ui-egui/src/i18n/de.tsv
index a3534cce1..7f1c43e6c 100644
--- a/crates/ui-egui/src/i18n/de.tsv
+++ b/crates/ui-egui/src/i18n/de.tsv
@@ -1865,6 +1865,7 @@ file-filter	Templates	Vorlagen
 	Miter Limit:	Gehrungsgrenze:
 	Mixed Appearances	Gemischtes Aussehen
 	Mixed Objects	Gemischte Objekte
+	Mixed	Gemischt
 	Mode:	Modus:
 	Model	Modell
 	Modified	Geändert
diff --git a/crates/ui-egui/src/i18n/el.tsv b/crates/ui-egui/src/i18n/el.tsv
index f537725c0..26de8c133 100644
--- a/crates/ui-egui/src/i18n/el.tsv
+++ b/crates/ui-egui/src/i18n/el.tsv
@@ -2616,6 +2616,7 @@ theme	Appearance	Εμφάνιση
 	Miter Limit:	Όριο οξείας σύνδεσης:
 	Mixed Appearances	Μεικτές εμφανίσεις
 	Mixed Objects	Μεικτά αντικείμενα
+	Mixed	Μικτό
 	Modified	Τροποποιήθηκε
 	Modified since it was read: {path}	Τροποποιήθηκε μετά την ανάγνωση: {path}
 	Modified:	Τροποποιήθηκε:
diff --git a/crates/ui-egui/src/i18n/es.tsv b/crates/ui-egui/src/i18n/es.tsv
index da1f4b362..f3ecd85fe 100644
--- a/crates/ui-egui/src/i18n/es.tsv
+++ b/crates/ui-egui/src/i18n/es.tsv
@@ -1863,6 +1863,7 @@ font-technology	Variable	Variables
 	Miter Limit:	Límite de inglete:
 	Mixed Appearances	Apariencias mixtas
 	Mixed Objects	Objetos mixtos
+	Mixed	Mixto
 	Mode:	Modo:
 	Model	Modelo
 	Modified	Modificado
diff --git a/crates/ui-egui/src/i18n/fi.tsv b/crates/ui-egui/src/i18n/fi.tsv
index 1ebb354f9..917393059 100644
--- a/crates/ui-egui/src/i18n/fi.tsv
+++ b/crates/ui-egui/src/i18n/fi.tsv
@@ -1333,6 +1333,7 @@ lighting	Light	Valo
 	Hide Thumbnail	Piilota pikkukuva
 	Mixed Appearances	Eri ulkoasuja
 	Mixed Objects	Eri objekteja
+	Mixed	Sekalainen
 	No options	Ei asetuksia
 	No Selection	Ei valintaa
 	Offset X	Siirtymä X
diff --git a/crates/ui-egui/src/i18n/fr.tsv b/crates/ui-egui/src/i18n/fr.tsv
index 943ca1140..e6b8a9459 100644
--- a/crates/ui-egui/src/i18n/fr.tsv
+++ b/crates/ui-egui/src/i18n/fr.tsv
@@ -1862,6 +1862,7 @@ font-technology	Variable	Variables
 	Miter Limit:	Limite de pointe :
 	Mixed Appearances	Aspects mixtes
 	Mixed Objects	Objets mixtes
+	Mixed	Mixte
 	Mode:	Mode :
 	Model	Modèle
 	Modified	Modifié
diff --git a/crates/ui-egui/src/i18n/hu.tsv b/crates/ui-egui/src/i18n/hu.tsv
index 670c93a99..84b1cc37b 100644
--- a/crates/ui-egui/src/i18n/hu.tsv
+++ b/crates/ui-egui/src/i18n/hu.tsv
@@ -2365,6 +2365,7 @@ file-filter	Templates	Sablonok
 	Miter Limit:	Hegyesszög-határ:
 	Mixed Appearances	Vegyes megjelenések
 	Mixed Objects	Vegyes objektumok
+	Mixed	Vegyes
 	Mobile	Mobil
 	Mode	Mód
 	Mode:	Mód:
diff --git a/crates/ui-egui/src/i18n/id.tsv b/crates/ui-egui/src/i18n/id.tsv
index c91631178..4d813f3ba 100644
--- a/crates/ui-egui/src/i18n/id.tsv
+++ b/crates/ui-egui/src/i18n/id.tsv
@@ -1276,6 +1276,7 @@ lighting	Light	Cahaya
 	Hide Thumbnail	Sembunyikan thumbnail
 	Mixed Appearances	Penampilan campuran
 	Mixed Objects	Objek campuran
+	Mixed	Campuran
 	No options	Tidak ada opsi
 	No Selection	Tidak ada seleksi
 	Offset X	Offset X
diff --git a/crates/ui-egui/src/i18n/it.tsv b/crates/ui-egui/src/i18n/it.tsv
index cf329b283..8a065733e 100644
--- a/crates/ui-egui/src/i18n/it.tsv
+++ b/crates/ui-egui/src/i18n/it.tsv
@@ -1890,6 +1890,7 @@ file-filter	Templates	Modelli
 	Miter Limit:	Limite angolo vivo:
 	Mixed Appearances	Aspetti misti
 	Mixed Objects	Oggetti misti
+	Mixed	Misto
 	Mode:	Modalità:
 	Model	Modello
 	Modified	Modificato
diff --git a/crates/ui-egui/src/i18n/ja.tsv b/crates/ui-egui/src/i18n/ja.tsv
index 7449d1f09..6e6ed4a70 100644
--- a/crates/ui-egui/src/i18n/ja.tsv
+++ b/crates/ui-egui/src/i18n/ja.tsv
@@ -3510,6 +3510,7 @@ file-filter	Templates	テンプレート
 	Miter Limit	角の比率
 	Miter Limit:	角の比率:
 	Mixed Objects	混在したオブジェクト
+	Mixed	混在
 	Model	モデル
 	Move All Objects	すべてのオブジェクトを移動
 	N pt per	N pt ごと
diff --git a/crates/ui-egui/src/i18n/ka.tsv b/crates/ui-egui/src/i18n/ka.tsv
index b22d3d09a..d85bbf2f1 100644
--- a/crates/ui-egui/src/i18n/ka.tsv
+++ b/crates/ui-egui/src/i18n/ka.tsv
@@ -1192,6 +1192,7 @@ lighting	Light	სინათლე
 	Hide Thumbnail	ესკიზის დამალვა
 	Mixed Appearances	შერეული იერსახეები
 	Mixed Objects	შერეული ობიექტები
+	Mixed	შერეული
 	No options	პარამეტრები არ არის
 	No Selection	მონიშნული არაფერია
 	Offset X	X-წანაცვლება
diff --git a/crates/ui-egui/src/i18n/ko.tsv b/crates/ui-egui/src/i18n/ko.tsv
index 6d64b057b..a6bccad0b 100644
--- a/crates/ui-egui/src/i18n/ko.tsv
+++ b/crates/ui-egui/src/i18n/ko.tsv
@@ -3503,6 +3503,7 @@ file-filter	Templates	템플릿
 	Miter Limit	모퉁이 한계
 	Miter Limit:	모퉁이 한계:
 	Mixed Objects	혼합 개체
+	Mixed	혼합
 	Model	모델
 	Move All Objects	모든 개체 이동
 	N pt per	당 N pt
diff --git a/crates/ui-egui/src/i18n/nl.tsv b/crates/ui-egui/src/i18n/nl.tsv
index b0e9ed9b8..d53f44c37 100644
--- a/crates/ui-egui/src/i18n/nl.tsv
+++ b/crates/ui-egui/src/i18n/nl.tsv
@@ -1290,6 +1290,7 @@ lighting	Light	Licht
 	Hide Thumbnail	Miniatuur verbergen
 	Mixed Appearances	Gemengde vormgevingen
 	Mixed Objects	Gemengde objecten
+	Mixed	Gemengd
 	No options	Geen opties
 	No Selection	Geen selectie
 	Offset X	Verschuiving X
diff --git a/crates/ui-egui/src/i18n/pl.tsv b/crates/ui-egui/src/i18n/pl.tsv
index 8a52c4c51..e1ccecb25 100644
--- a/crates/ui-egui/src/i18n/pl.tsv
+++ b/crates/ui-egui/src/i18n/pl.tsv
@@ -1273,6 +1273,7 @@ lighting	Light	Światło
 	Hide Thumbnail	Ukryj miniaturę
 	Mixed Appearances	Różne wyglądy
 	Mixed Objects	Różne obiekty
+	Mixed	Mieszane
 	No options	Brak opcji
 	No Selection	Brak zaznaczenia
 	Offset X	Odsunięcie X
diff --git a/crates/ui-egui/src/i18n/pt-br.tsv b/crates/ui-egui/src/i18n/pt-br.tsv
index 7b0a0e623..d4fc9c9a7 100644
--- a/crates/ui-egui/src/i18n/pt-br.tsv
+++ b/crates/ui-egui/src/i18n/pt-br.tsv
@@ -4455,6 +4455,7 @@ axis	Both	Ambos
 	Miter Limit	Limite da Ponta
 	Miter Limit:	Limite da Ponta:
 	Mixed Objects	Objetos Mistos
+	Mixed	Misto
 	Mojikumi	Mojikumi
 	Move All Objects	Mover Todos os Objetos
 	N pt per	N pt por
diff --git a/crates/ui-egui/src/i18n/ru.tsv b/crates/ui-egui/src/i18n/ru.tsv
index 59f8cd4f0..972f4a2b2 100644
--- a/crates/ui-egui/src/i18n/ru.tsv
+++ b/crates/ui-egui/src/i18n/ru.tsv
@@ -1888,6 +1888,7 @@ file-filter	Templates	Шаблоны
 	Miter Limit:	Предел митры:
 	Mixed Appearances	Смешанное оформление
 	Mixed Objects	Смешанные объекты
+	Mixed	Смешанное
 	Mode:	Режим:
 	Model	Модель
 	Modified	Изменено
diff --git a/crates/ui-egui/src/i18n/sv.tsv b/crates/ui-egui/src/i18n/sv.tsv
index c46f2970f..b755101a8 100644
--- a/crates/ui-egui/src/i18n/sv.tsv
+++ b/crates/ui-egui/src/i18n/sv.tsv
@@ -1813,6 +1813,7 @@ font-technology	Variable	Variabla
 	Miter Limit:	Spetsgräns:
 	Mixed Appearances	Blandade utseenden
 	Mixed Objects	Blandade objekt
+	Mixed	Blandat
 	Mode:	Läge:
 	Model	Modell
 	Modified	Ändrad
diff --git a/crates/ui-egui/src/i18n/tr.tsv b/crates/ui-egui/src/i18n/tr.tsv
index ce6b2229e..cc84fbb5d 100644
--- a/crates/ui-egui/src/i18n/tr.tsv
+++ b/crates/ui-egui/src/i18n/tr.tsv
@@ -1710,6 +1710,7 @@ font-technology	Variable	Değişken
 	Miter Limit:	Gönye Sınırı:
 	Mixed Appearances	Karışık Görünümler
 	Mixed Objects	Karışık Nesneler
+	Mixed	Karışık
 	Mode:	Mod:
 	Model	Modeli
 	Modified	Değiştirildi
diff --git a/crates/ui-egui/src/i18n/uk.tsv b/crates/ui-egui/src/i18n/uk.tsv
index 65384df71..32f3ba05c 100644
--- a/crates/ui-egui/src/i18n/uk.tsv
+++ b/crates/ui-egui/src/i18n/uk.tsv
@@ -1884,6 +1884,7 @@ file-filter	Templates	Шаблони
 	Miter Limit:	Межа гострого з’єднання:
 	Mixed Appearances	Змішане оформлення
 	Mixed Objects	Змішані об’єкти
+	Mixed	Змішане
 	Mode:	Режим:
 	Model	Модель
 	Modified	Змінено
diff --git a/crates/ui-egui/src/i18n/vi.tsv b/crates/ui-egui/src/i18n/vi.tsv
index d9ab99612..01be6b1e7 100644
--- a/crates/ui-egui/src/i18n/vi.tsv
+++ b/crates/ui-egui/src/i18n/vi.tsv
@@ -2177,6 +2177,7 @@ file-filter	Templates	Mẫu
 	Miter Limit:	Giới hạn góc nhọn:
 	Mixed Appearances	Diện mạo hỗn hợp
 	Mixed Objects	Đối tượng hỗn hợp
+	Mixed	Hỗn hợp
 	Mode	Chế độ
 	Mode:	Chế độ:
 	Model	Mô hình
diff --git a/crates/ui-egui/src/i18n/zh-hans.tsv b/crates/ui-egui/src/i18n/zh-hans.tsv
index 0daa3138f..599fe0e80 100644
--- a/crates/ui-egui/src/i18n/zh-hans.tsv
+++ b/crates/ui-egui/src/i18n/zh-hans.tsv
@@ -1770,6 +1770,7 @@ file-filter	Templates	模板
 	Miter Limit:	斜接限制：
 	Mixed Appearances	混合外观
 	Mixed Objects	混杂对象
+	Mixed	混合
 	Mode:	模式：
 	Model	模型
 	Modified	已修改
diff --git a/crates/ui-egui/src/i18n/zh-hant.tsv b/crates/ui-egui/src/i18n/zh-hant.tsv
index 533516327..8f19370ad 100644
--- a/crates/ui-egui/src/i18n/zh-hant.tsv
+++ b/crates/ui-egui/src/i18n/zh-hant.tsv
@@ -2648,6 +2648,7 @@ file-filter	Templates	範本
 	Miter Limit:	尖角限度：
 	Mixed Appearances	混合外觀
 	Mixed Objects	混雜物件
+	Mixed	混合
 	Mode:	模式：
 	Model	模型
 	Modified	已修改
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 9d8bc5937..b1337be67 100644
--- a/crates/ui-egui/src/panels/appearance.rs
+++ b/crates/ui-egui/src/panels/appearance.rs
@@ -255,8 +255,9 @@ pub fn show(app: &mut VectorcraftApp, ui: &mut Ui) {
             select_row(app, ui.ctx(), Sel::None);
         }
         ui.painter().line_segment([r.left_bottom(), r.right_bottom()], Stroke::new(1.0, t.input_border));
-        let mixed = mixed_appearances(app);
-        let label = if mixed { tl!("Mixed Appearances") } else { tl!(object_label(app)) };
+        let mix = mixed(app);
+        let mixed = mix.is_some();
+        let label = tl!(object_label(app));
         // A linked object names its graphic style ("Rectangle: Sunshine"), and so does new art
         // with nothing selected.
         let style = match app.session.selection_graphic_style() {
@@ -270,7 +271,12 @@ pub fn show(app: &mut VectorcraftApp, ui: &mut Ui) {
         };
         if !hide_thumb {
             let th = Rect::from_min_size(r.left_center() + vec2(6.0, -12.0), vec2(24.0, 24.0));
-            let fill = node.as_ref().map(|n| n.appearance.fill_paint()).unwrap_or_else(|| app.session.paint.fill.clone());
+            // Objects whose fills differ show no one of them.
+            let fill = match &node {
+                Some(_) if mix.as_ref().is_some_and(|m| m.fills_differ) => Paint::None,
+                Some(n) => n.appearance.fill_paint(),
+                None => app.session.paint.fill.clone(),
+            };
             chip(ui, th, &fill);
             if let Some(n) = node.as_ref().filter(|_| !mixed) {
                 thumbnail_drag(ui, th, n.id);
@@ -278,9 +284,19 @@ pub fn show(app: &mut VectorcraftApp, ui: &mut Ui) {
         }
         text(ui, r.left_center() + vec2(if hide_thumb { 8.0 } else { 46.0 }, 0.0), &label, true);
         match &node {
-            // Objects that differ have no common stack to list.
-            Some(_) if mixed => {}
-            Some(n) => stack(app, ui, n, sel, r),
+            // Objects that differ list what they share, under a note that they differ.
+            Some(n) if let Some(m) = &mix => {
+                let (mr, _) = ui.allocate_exact_size(vec2(ui.available_width(), ROW), Sense::hover());
+                let mut job = egui::text::LayoutJob::default();
+                let format = egui::TextFormat { font_id: egui::FontId::proportional(12.0), color: t.text_dim, italics: true, ..Default::default() };
+                job.append(tl!("Mixed Appearances"), 0.0, format);
+                let g = ui.painter().layout_job(job);
+                ui.painter().galley(mr.left_center() + vec2(EYE_W + 24.0, -g.size().y / 2.0), g, t.text_dim);
+                if !(m.shared.items.is_empty() && m.shared.effects.is_empty()) {
+                    stack(app, ui, n, sel, r, Some(m));
+                }
+            }
+            Some(n) => stack(app, ui, n, sel, r, None),
             None => default_stack(app, ui),
         }
         // Spacer row like Illustrator's empty tail.
@@ -306,23 +322,54 @@ fn first_subject(app: &VectorcraftApp) -> Option<Node> {
     st.selection.subjects().first().and_then(|id| st.doc.node(*id)).cloned()
 }
 
-/// The selection as the Control bar and the object row name it: "No Selection", "Mixed Objects"
-/// or the kind ("Path", "Type", "Layer"…) of the object, or targeted layer, the panel lists.
+/// The selection as the Control bar and the object row name it: "No Selection", the kind ("Path",
+/// "Type", "Layer"…) of the object, or targeted layer, the panel lists, or of every selected
+/// object when they are all of one kind, else "Mixed Objects".
 pub(crate) fn object_label(app: &VectorcraftApp) -> &'static str {
     let Some(st) = app.session.active() else { return "No Selection" };
-    match st.selection.subjects() {
-        [] => "No Selection",
-        [id] => st.doc.node(*id).map_or("No Selection", Node::kind_label),
-        _ => "Mixed Objects",
-    }
+    let mut kinds = st.selection.subjects().iter().map(|id| st.doc.node(*id).map_or("No Selection", Node::kind_label));
+    let Some(first) = kinds.next() else { return "No Selection" };
+    if kinds.all(|k| k == first) { first } else { "Mixed Objects" }
 }
 
-/// Do the selected objects differ in appearance (fills, strokes, effects, opacity or blend mode)?
-fn mixed_appearances(app: &VectorcraftApp) -> bool {
-    let Some(st) = app.session.active() else { return false };
-    let mut nodes = st.selection.subjects().iter().filter_map(|id| st.doc.node(*id));
-    let Some(first) = nodes.next() else { return false };
-    nodes.any(|n| n.appearance != first.appearance || n.opacity != first.opacity || n.blend != first.blend)
+/// The selected objects the panel lists (several, at least one differing from the first in
+/// appearance, opacity or blend mode): what their stacks share, and whether their opacity and blend
+/// mode differ. `None` for one object, or several alike.
+fn mixed(app: &VectorcraftApp) -> Option<Mixed> {
+    let st = app.session.active()?;
+    let nodes: Vec<&Node> = st.selection.subjects().iter().filter_map(|id| st.doc.node(*id)).collect();
+    let (first, rest) = nodes.split_first()?;
+    let transparency = rest.iter().any(|n| n.opacity != first.opacity || n.blend != first.blend);
+    if rest.is_empty() || (!transparency && rest.iter().all(|n| n.appearance == first.appearance)) {
+        return None;
+    }
+    let aps: Vec<&vectorcraft_doc::Appearance> = nodes.iter().map(|n| &*n.appearance).collect();
+    let fills_differ = rest.iter().any(|n| n.appearance.fill_paint() != first.appearance.fill_paint());
+    Some(Mixed { shared: vectorcraft_doc::appearance::SharedStack::of(&aps), transparency, fills_differ })
+}
+
+/// A mixed selection as the panel lists it ([`mixed`]).
+struct Mixed {
+    /// The fills, strokes and effects the objects share: the rows listed.
+    shared: vectorcraft_doc::appearance::SharedStack,
+    /// The objects' opacity or blend mode differ: the Opacity row reads "Mixed".
+    transparency: bool,
+    /// Their topmost fills differ: the object row shows no fill chip.
+    fills_differ: bool,
+}
+
+/// `params` of an item or effect command the panel runs, with `aligned` when the selected objects'
+/// stacks differ: its indices are then rows of the first object's stack, which each other object
+/// edits where it has them (the panel lists only the rows they share).
+fn aligned(app: &VectorcraftApp, mut params: Value) -> Value {
+    let differ = app.session.active().is_some_and(|st| {
+        let mut aps = st.selection.subjects().iter().filter_map(|id| st.doc.node(*id)).map(|n| &n.appearance);
+        aps.next().is_some_and(|first| aps.any(|a| a != first))
+    });
+    if differ && let Some(m) = params.as_object_mut() {
+        m.insert("aligned".into(), json!(true));
+    }
+    params
 }
 
 /// What the next object drawn gets when nothing is selected (`Session::new_art`): its fills and
@@ -393,23 +440,33 @@ enum Slot {
     Contents,
 }
 
-fn stack(app: &mut VectorcraftApp, ui: &mut Ui, n: &Node, sel: Sel, object_row: Rect) {
+/// `only`: a mixed selection (`n` its first object): only the rows its objects share are listed,
+/// and rows aren't dragged (where one would go in each of the different stacks isn't one place).
+fn stack(app: &mut VectorcraftApp, ui: &mut Ui, n: &Node, sel: Sel, object_row: Rect, only: Option<&Mixed>) {
     let t = Tokens::get(ui.ctx());
     let ctx = ui.ctx().clone();
-    let dragging: Option<Dragged> = pstate(&ctx, "ap-drag");
+    let dragging: Option<Dragged> = pstate::<Option<Dragged>>(&ctx, "ap-drag").filter(|_| only.is_none());
     let items = selected_items(&ctx, Some(n), sel);
     let mut rows = vec![(Slot::Object { top: true }, object_row)];
     let mut stopped = false;
     // Starts or ends a row drag.
+    let frozen = only.is_some();
     let mut track = |resp: &egui::Response, what: Dragged| {
+        if frozen {
+            return;
+        }
         if resp.drag_started() {
             set_pstate(&ctx, "ap-drag", Some(what));
         }
         stopped |= resp.drag_stopped();
     };
-    let contents = n.contents_label();
+    // A mixed selection's Contents rows differ object by object: none is listed.
+    let contents = n.contents_label().filter(|_| only.is_none());
     let below = n.appearance.contents_at();
     for (i, it) in n.appearance.items.iter().enumerate().rev() {
+        if only.is_some_and(|m| !m.shared.has_item(i)) {
+            continue;
+        }
         // The Contents row sits right above the items painted below the members.
         if let Some(label) = contents.filter(|_| i + 1 == below) {
             let (r, resp) = contents_row(app, ui, n, label, sel);
@@ -422,7 +479,7 @@ fn stack(app: &mut VectorcraftApp, ui: &mut Ui, n: &Node, sel: Sel, object_row:
         let (visible, paint) = (it.visible(), it.paint());
         let is_stroke = !it.is_fill();
         if eye(ui, r, ("ap-eye", i), visible, true) {
-            app.run("appearance.setItem", json!({"index": i, "visible": !visible})).ok();
+            app.run("appearance.setItem", aligned(app, json!({"index": i, "visible": !visible}))).ok();
         }
         if chevron(ui, r, ("ap-chev", i), open) {
             set_pstate(ui.ctx(), &format!("ap-open-{i}"), !open);
@@ -456,7 +513,7 @@ fn stack(app: &mut VectorcraftApp, ui: &mut Ui, n: &Node, sel: Sel, object_row:
             let mut child = ui.new_child(egui::UiBuilder::new().max_rect(fr).layout(egui::Layout::left_to_right(egui::Align::Center)));
             if let Some(w) = widgets::num_field_named(&mut child, ("ap-w", i), Some(tl!("Weight:")), Some(st.width), app.session.stroke_unit(), 56.0)
             {
-                app.run("appearance.setItem", json!({"index": i, "weight": w})).ok();
+                app.run("appearance.setItem", aligned(app, json!({"index": i, "weight": w}))).ok();
             }
             stroke_notes(ui, Rect::from_min_max(pos2(fr.right() + 6.0, r.top()), pos2(r.right() - 4.0, r.bottom())), st);
         }
@@ -469,7 +526,7 @@ fn stack(app: &mut VectorcraftApp, ui: &mut Ui, n: &Node, sel: Sel, object_row:
         }
         track(&resp, Dragged::Item(i));
         if open {
-            let r = opacity_row(app, ui, Some(i), it.opacity(), it.blend());
+            let r = opacity_row(app, ui, Some(i), it.opacity(), it.blend(), false);
             rows.push((Slot::Item { index: i, sub: true }, r));
             for (k, e) in it.effects().iter().enumerate() {
                 let (r, resp) = effect_row(app, ui, Some(i), k, e, sel == Sel::ItemEffect(i, k));
@@ -485,11 +542,14 @@ fn stack(app: &mut VectorcraftApp, ui: &mut Ui, n: &Node, sel: Sel, object_row:
     }
     // Object-level effects.
     for (k, e) in n.appearance.effects.iter().enumerate() {
+        if only.is_some_and(|m| !m.shared.has_effect(k)) {
+            continue;
+        }
         let (r, resp) = effect_row(app, ui, None, k, e, sel == Sel::Effect(k));
         rows.push((Slot::Effect(None, k), r));
         track(&resp, Dragged::Effect(None, k));
     }
-    let r = opacity_row(app, ui, None, n.opacity, n.blend);
+    let r = opacity_row(app, ui, None, n.opacity, n.blend, only.is_some_and(|m| m.transparency));
     rows.push((Slot::Object { top: false }, r));
     let Some(what) = dragging else { return };
     let pointer = ui.ctx().pointer_interact_pos();
@@ -669,17 +729,24 @@ fn stroke_notes(ui: &Ui, r: Rect, st: &vectorcraft_doc::StrokeLayer) {
 /// The Opacity row of the object (`item: None`) or, indented, of fill/stroke `item`. Clicking it
 /// opens a popup with the shared opacity and blend controls (`transparency.set` on that item).
 /// Returns the row's rect.
-fn opacity_row(app: &mut VectorcraftApp, ui: &mut Ui, item: Option<usize>, opacity: f32, blend: BlendMode) -> Rect {
+///
+/// `mixed`: the selected objects' opacity or blend mode differ: it reads "Mixed", and an edit
+/// sets them all.
+fn opacity_row(app: &mut VectorcraftApp, ui: &mut Ui, item: Option<usize>, opacity: f32, blend: BlendMode, mixed: bool) -> Rect {
     let (r, resp) = row(ui, false);
     eye(ui, r, ("ap-op-eye", item), true, false);
     let lx = r.left() + EYE_W + 24.0 + if item.is_some() { 12.0 } else { 0.0 };
     let clicked = link(ui, pos2(lx, r.center().y), ("ap-op-link", item), tl!("Opacity:")) || resp.clicked();
-    text(ui, pos2(lx + 56.0, r.center().y), &opacity_text(opacity, blend), false);
+    let shown = if mixed { tl!("Mixed").to_string() } else { opacity_text(opacity, blend) };
+    text(ui, pos2(lx + 56.0, r.center().y), &shown, false);
     widgets::popover(&resp, clicked, |ui| match widgets::opacity_blend(ui, ("ap-op", item), Some(opacity), Some(blend), true) {
         Some(TransparencyEdit::Blend(b)) => {
-            app.run("transparency.set", json!({"item": item, "blend": b.label()})).ok();
+            app.run("transparency.set", aligned(app, json!({"item": item, "blend": b.label()}))).ok();
+        }
+        Some(TransparencyEdit::Opacity(o, phase)) => {
+            let params = aligned(app, json!({"item": item, "opacity": o}));
+            live_run(app, "Opacity", "transparency.set", params, phase)
         }
-        Some(TransparencyEdit::Opacity(o, phase)) => live_run(app, "Opacity", "transparency.set", json!({"item": item, "opacity": o}), phase),
         None => {}
     });
     r
@@ -696,7 +763,7 @@ fn effect_row(app: &mut VectorcraftApp, ui: &mut Ui, item: Option<usize>, k: usi
     let (row_rect, resp) = row(ui, selected);
     let r = row_rect;
     if eye(ui, r, ("ap-fx-eye", item, k), e.visible, true) {
-        app.run("effect.setParams", json!({"item": item, "index": k, "visible": !e.visible})).ok();
+        app.run("effect.setParams", aligned(app, json!({"item": item, "index": k, "visible": !e.visible}))).ok();
     }
     let indent = if item.is_some() { 12.0 } else { 0.0 };
     let r = Rect::from_min_max(pos2(r.left() + indent, r.top()), r.max);
@@ -707,7 +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);
         }
@@ -846,10 +913,10 @@ fn effect_editor(app: &mut VectorcraftApp, ui: &mut Ui, item: Option<usize>, k:
         }
     });
     if let Some((key, v)) = change {
-        app.run("effect.setParams", json!({"item": item, "index": k, "params": {key: v}})).ok();
+        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();
     }
 }
 
@@ -892,7 +959,7 @@ fn swatch_picker(app: &mut VectorcraftApp, ui: &mut Ui, index: usize) {
     });
     if let Some((name, none)) = chosen {
         let params = if none { json!({"index": index, "none": true}) } else { json!({"index": index, "swatch": name}) };
-        app.run("appearance.setItem", params).ok();
+        app.run("appearance.setItem", aligned(app, params)).ok();
         ui.close();
     }
 }
@@ -929,16 +996,20 @@ fn bottom(app: &mut VectorcraftApp, ui: &mut Ui, node: Option<&Node>, sel: Sel)
 /// Duplicate the selected fills/strokes (each copy right above its row) or the selected effect.
 fn duplicate_selected(app: &mut VectorcraftApp, ui: &Ui, node: Option<&Node>, sel: Sel) {
     match sel.effect() {
-        Some(fx) => app.run("effect.duplicate", fx).ok(),
-        None if sel.item().is_some() => app.run("appearance.duplicateItem", json!({"indices": selected_items(ui.ctx(), node, sel)})).ok(),
+        Some(fx) => app.run("effect.duplicate", aligned(app, fx)).ok(),
+        None if sel.item().is_some() => {
+            app.run("appearance.duplicateItem", aligned(app, json!({"indices": selected_items(ui.ctx(), node, sel)}))).ok()
+        }
         None => None,
     };
 }
 
 fn delete_selected(app: &mut VectorcraftApp, ui: &Ui, node: Option<&Node>, sel: Sel) {
     let ok = match sel.effect() {
-        Some(fx) => app.run("effect.remove", fx).is_ok(),
-        None if sel.item().is_some() => app.run("appearance.removeItem", json!({"indices": selected_items(ui.ctx(), node, sel)})).is_ok(),
+        Some(fx) => app.run("effect.remove", aligned(app, fx)).is_ok(),
+        None if sel.item().is_some() => {
+            app.run("appearance.removeItem", aligned(app, json!({"indices": selected_items(ui.ctx(), node, sel)}))).is_ok()
+        }
         None => false,
     };
     // Removing the active item clears it in the engine; a removed item effect leaves its item
diff --git a/crates/ui-egui/src/panels/appearance/tests.rs b/crates/ui-egui/src/panels/appearance/tests.rs
index 5df314659..73f0eacf9 100644
--- a/crates/ui-egui/src/panels/appearance/tests.rs
+++ b/crates/ui-egui/src/panels/appearance/tests.rs
@@ -534,3 +534,37 @@ fn inline_stroke_weight_and_effect_fields_are_named() {
     let _ = h.get_by_role_and_label(egui::accesskit::Role::TextInput, "Blur");
     let _ = h.get_by_role_and_label(egui::accesskit::Role::RadioButton, "Color");
 }
+
+/// #4174: two circles with different fills and the same stroke, effect and opacity list the
+/// object row with their kind, the "Mixed Appearances" note and what they share: the stroke, the
+/// Feather and the opacity, not the fills. A path with type names them "Mixed Objects".
+#[test]
+fn a_mixed_selection_lists_what_its_objects_share() {
+    let mut app = VectorcraftApp::new(vectorcraft_engine::Session::new(), Default::default());
+    let run = |app: &mut VectorcraftApp, id: &str, p: Value| app.session.execute(id, &p).unwrap();
+    run(&mut app, "file.new", json!({"width": 300, "height": 200}));
+    let mut ids = vec![];
+    for (x, color) in [(0, "#ffff00"), (150, "#ff0000")] {
+        let id = run(&mut app, "shape.ellipse", json!({"x": x, "y": 50, "width": 100, "height": 100}))["id"].clone();
+        run(&mut app, "paint.setFill", json!({"ids": [id], "color": color}));
+        run(&mut app, "appearance.setItem", json!({"ids": [id], "index": 1, "color": "#0000ff", "weight": 11}));
+        run(&mut app, "effect.apply", json!({"ids": [id], "effect": "stylize.feather", "item": null}));
+        ids.push(id);
+    }
+    run(&mut app, "select.set", json!({"ids": ids}));
+    let shown = frame(&mut app);
+    let kind = app.session.active().unwrap().doc.node(vectorcraft_doc::NodeId(ids[0].as_u64().unwrap())).unwrap().kind_label();
+    assert_eq!(shown.first().map(String::as_str), Some(kind), "the object row names their kind: {shown:?}");
+    assert!(shown.iter().any(|t| t == "Mixed Appearances"), "{shown:?}");
+    assert!(shown.iter().any(|t| t == "Stroke:") && !shown.iter().any(|t| t == "Fill:"), "the stroke, not the fills: {shown:?}");
+    assert!(shown.iter().any(|t| t.contains("Feather")), "the shared effect: {shown:?}");
+    assert!(shown.iter().any(|t| t == "Opacity:"), "{shown:?}");
+    // Alike objects list their whole stack, without the note.
+    run(&mut app, "paint.setFill", json!({"ids": ids, "color": "#ffff00"}));
+    let shown = frame(&mut app);
+    assert!(!shown.iter().any(|t| t == "Mixed Appearances") && shown.iter().any(|t| t == "Fill:"), "{shown:?}");
+    // A path and type.
+    let t = run(&mut app, "text.create", json!({"x": 0, "y": 180, "text": "Hi"}))["id"].clone();
+    run(&mut app, "select.set", json!({"ids": [ids[0].clone(), t]}));
+    assert_eq!(frame(&mut app).first().map(String::as_str), Some("Mixed Objects"));
+}
diff --git a/crates/ui-egui/src/panels/tests_appearance.rs b/crates/ui-egui/src/panels/tests_appearance.rs
index c7569841e..ed3e26892 100644
--- a/crates/ui-egui/src/panels/tests_appearance.rs
+++ b/crates/ui-egui/src/panels/tests_appearance.rs
@@ -324,16 +324,18 @@ fn object_row_names_the_selection_like_the_control_bar() {
     let ctx = egui::Context::default();
     assert!(frame_in(&ctx, &mut app, appearance::show).contains(&"Rectangle".to_string()));
     let b = run(&mut app, "shape.rectangle", json!({"x": 120, "y": 10, "width": 50, "height": 50}))["id"].clone();
-    // Objects with one appearance list it under "Mixed Objects".
+    // Objects of one kind with one appearance are named by their kind and list it (#4174).
     run(&mut app, "select.set", json!({"ids": [a, b]}));
     let texts = frame_in(&ctx, &mut app, appearance::show);
-    assert!(texts.contains(&"Mixed Objects".to_string()) && texts.contains(&"Stroke:".to_string()), "{texts:?}");
-    // Objects that differ list nothing.
+    assert!(texts.contains(&"Rectangle".to_string()) && texts.contains(&"Stroke:".to_string()), "{texts:?}");
+    assert!(!texts.contains(&"Mixed Appearances".to_string()), "{texts:?}");
+    // Objects whose opacity differs list what they share, the opacity as mixed.
     run(&mut app, "select.set", json!({"ids": [b]}));
     run(&mut app, "transparency.set", json!({"opacity": 50}));
     run(&mut app, "select.set", json!({"ids": [a, b]}));
     let texts = frame_in(&ctx, &mut app, appearance::show);
-    assert!(texts.contains(&"Mixed Appearances".to_string()) && !texts.contains(&"Stroke:".to_string()), "{texts:?}");
+    assert!(texts.contains(&"Mixed Appearances".to_string()) && texts.contains(&"Stroke:".to_string()), "{texts:?}");
+    assert!(texts.contains(&"Mixed".to_string()), "the opacity reads Mixed: {texts:?}");
     // Type objects are "Type" in both places.
     let t = run(&mut app, "text.create", json!({"x": 10, "y": 150, "text": "Hi"}))["id"].clone();
     run(&mut app, "select.set", json!({ "ids": [t] }));