diff --git a/crates/engine/src/cmd/opacitymask.rs b/crates/engine/src/cmd/opacitymask.rs
index 52622c79..135e50ff 100644
--- a/crates/engine/src/cmd/opacitymask.rs
+++ b/crates/engine/src/cmd/opacitymask.rs
@@ -250,6 +250,18 @@ fn set_flags(s: &mut Session, target: &Value, label: &str, p: &Value) -> Result<
         return Err(bad("transparency.setOpacityMask", "give at least one of clip, invert, disabled, linked"));
     }
     let ids = masked_targets(s, target)?;
+    // When every mask already has the flags given, the document and its undo history stay as they
+    // are.
+    let has_flags = |m: &OpacityMask| {
+        clip.is_none_or(|v| m.clip == v)
+            && invert.is_none_or(|v| m.invert == v)
+            && disabled.is_none_or(|v| m.disabled == v)
+            && linked.is_none_or(|v| m.linked == v)
+    };
+    let d = &s.doc()?.doc;
+    if ids.iter().all(|id| d.node(*id).and_then(|n| n.mask.as_deref()).is_none_or(has_flags)) {
+        return ok();
+    }
     s.edit(label, |d, _| {
         for id in &ids {
             if let Some(m) = d.node_mut(*id).and_then(|n| n.mask.as_mut()) {
diff --git a/crates/engine/src/tests.rs b/crates/engine/src/tests.rs
index af911a8f..a8505146 100644
--- a/crates/engine/src/tests.rs
+++ b/crates/engine/src/tests.rs
@@ -571,13 +571,13 @@ fn selection_tool_drag_is_one_undo_step() {
 }
 
 /// How many steps there are to undo and to redo, and whether the document has unsaved changes.
-fn history(s: &Session) -> (usize, usize, bool) {
+pub(crate) fn history(s: &Session) -> (usize, usize, bool) {
     let st = s.doc().unwrap();
     (st.history.undo.len(), st.history.redo.len(), st.is_dirty())
 }
 
 /// Select `ids` with a move of them left to redo, and mark the document saved.
-fn select_with_a_step_to_redo(s: &mut Session, ids: &[NodeId]) {
+pub(crate) fn select_with_a_step_to_redo(s: &mut Session, ids: &[NodeId]) {
     s.execute("select.set", &json!({"ids": ids.iter().map(|i| i.0).collect::<Vec<_>>()})).unwrap();
     s.execute("object.move", &json!({"dx": 5, "dy": 0})).unwrap();
     s.execute("edit.undo", &json!({})).unwrap();
diff --git a/crates/engine/src/tests_opacitymask.rs b/crates/engine/src/tests_opacitymask.rs
index 3cfba760..d18e033f 100644
--- a/crates/engine/src/tests_opacitymask.rs
+++ b/crates/engine/src/tests_opacitymask.rs
@@ -6,6 +6,7 @@ use serde_json::{Value, json};
 
 use super::*;
 use crate::cmd::maskedit::MASK_EDIT_LAYER;
+use crate::tests::{history, select_with_a_step_to_redo};
 
 fn session() -> Session {
     let mut s = Session::new();
@@ -67,6 +68,70 @@ fn mask_options_act_on_the_masked_object_while_editing() {
     assert_eq!((info["ids"].clone(), info["opacity"].clone(), info["editingMask"].clone()), (json!([obj.0]), json!(40.0), json!(obj.0)));
 }
 
+/// Disable, Enable, Unlink and Link Opacity Mask and Opacity Mask Options with the flags the masks
+/// already have record no undo step, on the selection, with ids and while the mask is being edited:
+/// the step to redo stays, the document stays unmodified and the journal still has the command. A
+/// call that changes a flag on one of the masks is one undo step. A target without a mask and a
+/// call that gives no flag are still errors.
+#[test]
+fn mask_options_already_set_record_no_undo_step() {
+    let mut s = session();
+    let masked = |s: &mut Session, x: f64| {
+        let (obj, m) = (rect(s, x, 100.0), rect(s, x, 50.0));
+        s.execute("select.set", &json!({"ids": [obj.0, m.0]})).unwrap();
+        s.execute("transparency.makeOpacityMask", &json!({})).unwrap();
+        obj
+    };
+    // `a`'s mask is as made (clipping, not inverted, enabled, linked); `b`'s has each flag the other
+    // way.
+    let (a, b) = (masked(&mut s, 0.0), masked(&mut s, 150.0));
+    s.execute("transparency.setOpacityMask", &json!({"id": b.0, "clip": false, "invert": true, "disabled": true, "linked": false})).unwrap();
+    select_with_a_step_to_redo(&mut s, &[a]);
+    let before = history(&s);
+    assert_eq!((before.1, before.2), (1, false), "a step to redo, and nothing unsaved");
+    let calls = [
+        ("transparency.enableOpacityMask", json!({})),
+        ("transparency.linkOpacityMask", json!({})),
+        ("transparency.setOpacityMask", json!({"clip": true, "invert": false, "disabled": false, "linked": true})),
+        ("transparency.disableOpacityMask", json!({"id": b.0})),
+        ("transparency.unlinkOpacityMask", json!({"ids": [b.0]})),
+        ("transparency.setOpacityMask", json!({"ids": [b.0], "clip": false, "invert": true})),
+    ];
+    for (id, p) in calls {
+        assert_eq!(s.execute(id, &p).unwrap(), Value::Null, "{id} {p}");
+        assert_eq!(history(&s), before, "{id} {p}");
+        assert_eq!(s.journal.last().unwrap(), &(id.to_string(), p));
+    }
+    // While `a`'s mask is edited, the selection is its mask art and the commands act on `a`.
+    s.execute("transparency.editOpacityMask", &json!({"id": a.0})).unwrap();
+    let art = s.doc().unwrap().selection.objects.clone();
+    select_with_a_step_to_redo(&mut s, &art);
+    let before = history(&s);
+    assert_eq!((before.1, before.2), (1, false), "a step to redo, and nothing unsaved while editing");
+    let calls = [
+        ("transparency.enableOpacityMask", json!({})),
+        ("transparency.linkOpacityMask", json!({})),
+        ("transparency.setOpacityMask", json!({"clip": true, "linked": true})),
+    ];
+    for (id, p) in calls {
+        assert_eq!(s.execute(id, &p).unwrap(), Value::Null, "{id} {p} while editing");
+        assert_eq!(history(&s), before, "{id} {p} while editing");
+        assert_eq!(s.journal.last().unwrap(), &(id.to_string(), p));
+    }
+    assert!(doc(&s).mask_edit.is_some(), "still editing");
+    // `b`'s mask is disabled and `a`'s is not: disabling both is one undo step, and it clears Redo.
+    s.execute("transparency.stopEditingOpacityMask", &json!({})).unwrap();
+    select_with_a_step_to_redo(&mut s, &[a, b]);
+    let undo = history(&s).0;
+    s.execute("transparency.disableOpacityMask", &json!({})).unwrap();
+    assert_eq!(history(&s), (undo + 1, 0, true));
+    assert!(mask(&s, a).unwrap().disabled && mask(&s, b).unwrap().disabled);
+    let plain = rect(&mut s, 0.0, 20.0);
+    let err = s.execute("transparency.enableOpacityMask", &json!({"id": plain.0})).unwrap_err();
+    assert!(err.to_string().contains("no target object has an opacity mask"), "{err}");
+    assert!(s.execute("transparency.setOpacityMask", &json!({"id": a.0})).is_err(), "no flag given");
+}
+
 #[test]
 fn release_while_editing_leaves_editing_first() {
     let mut s = session();
diff --git a/docs/target-app-parity.md b/docs/target-app-parity.md
index 0d5f22ea..0151fa3e 100644
--- a/docs/target-app-parity.md
+++ b/docs/target-app-parity.md
@@ -458,6 +458,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
 - **Type:** Character size, leading, baseline shift and horizontal-scale controls account for object/group transforms (#1034): exact document-point sizes, mixed-value display and keyboard increments, range edits, resettable horizontal stretch, undo/redo and native save/reopen (`tests_typescale`, Character panel tests). Point size is the transformed em-height axis, independent of glyph ink bounds; affine rotation, reflection and shear are retained. Group scaling still scales text; preserving font sizes is a separate enhancement. Behaviour reference: [Transform text](https://helpx.adobe.com/illustrator/desktop/design-with-text/edit-format-text/transform-text.html) (public documentation). Text Wrap, Type on a Path effects (Rainbow/Skew/3D Ribbon/Stair Step/Gravity) and Options (Flip, Align to Path, Spacing; OK keeps the type where it is), type on a path's start, centre and end brackets (Selection and Direct Selection drag them to set where the type runs, slide it along its path and, across the path, flip it: #429), Character and Paragraph Styles (override-preserving redefine), paragraph attributes per paragraph (alignment, indents, spacing, hyphenation, hanging punctuation, tab stops, paragraph style, direction, mojikumi and leading model; the Paragraph, Tabs and Paragraph Styles panels act on the paragraphs the Type tool's selection or caret touches, Return continues the paragraph's style, threads and SVG keep them), Area Type Options (rows/columns/inset/first baseline, vertical Align Top/Center/Bottom/Justify per row/column, reflowing non-rectangular frames and text wrap), threaded text across any closed shapes, Fit Headline, the Every-line Composer for justified and ragged text (paragraph-wide breaks for an even rag, Single-line per object from the Paragraph panel menu or `text.setFormat {composer}`). Area type resizes like Illustrator's type areas: a bounding-box handle drag (Selection tool) or Area Type Options Width/Height size the frame and the text reflows at its size (threads too); Direct Selection drags a frame corner or edge (`text.reshapeArea`). Point type still scales. Auto Size: the frame height follows the text after every edit, in the same undo step (rectangular frames of horizontal type in one row; columns get the least height that holds them; a height set by hand or threading turns it off), and the "Auto Size New Area Type" preference gives it to new area type. Shrink Text to Fit (beyond Illustrator): overflowing area type scales its sizes, leading and baseline shifts down by the largest factor (in 0.1 pt steps of the first run, down to a minimum percentage) that fits, at layout time so every export sees it. `text.areaOptions` and `document.inspect` report overflow and the shrink factor. The Selection tool shows the type widget beside selected type's bounding box (hollow on point type, filled on area type); double-clicking it converts between them (Type › Convert To Area Type / Convert To Point Type), keeping the text and its styles in place. Variable fonts list every named instance as a style of their family (Figtree Light to Black and their italics, Bahnschrift, Segoe UI Variable), and the instance chosen is shaped, drawn, outlined and measured at its axis settings; PDF and SVG embed it as that instance. Variation axis sliders are not done. Beyond Illustrator: inline graphics (`text.insertInline`, Type ▸ Insert Inline Symbol) set a document symbol in a run of type as one character that flows, wraps and justifies like a glyph (InDesign-style inline objects, e.g. mana symbols in card rules text): sized to a multiple of the font size, centred on the cap height, opening up tall lines, following Redefine Symbol; a character of its run's size for Character Alignment and Top-to-Top leading, placed by the bidi reordering in right-to-left text (a neutral U+FFFC); drawn on the canvas, kept as live text plus a `<use>` in SVG and as vector art in PDF; Backspace removes it whole. Hebrew and Arabic are laid out right to left with the Unicode bidirectional algorithm (embedded Latin and numbers keep their direction, lines put in visual order after wrapping) in point, area and path type, with caret, selection and arrow keys in visual order; each paragraph's direction comes from its first strong character unless Paragraph Direction sets it (Paragraph panel with Show Indic Options, `text.setFormat {direction}`), and new type aligns to the start of its direction. SVG export outlines right-to-left text. Arabic typefaces: builds made with a craft-fonts checkout that holds its Arabic families (Noto Sans Arabic, the Arabic fallback, plus Cairo, Tajawal, Almarai, IBM Plex Sans Arabic, Noto Kufi Arabic, Amiri, Alexandria, Fustat, Reem Kufi, Aref Ruqaa and Gulzar once craft-fonts adds them, storytold/craft-fonts#11; releases get them when their craft-fonts pin moves) list them in the font menus on desktop; the web build fetches them from beside the wasm (Noto Sans Arabic before start, so Arabic never shows as boxes, the rest in the background). Font Size and Leading are combo boxes in the Character and Properties panels (Font Size in the Control bar too, beside the Character link, font family and style): type, step with ↑/↓ or the spinner, scrub the label, or pick a preset (6–72 pt, shown in the type unit; Leading also Auto), each pick one undo step; Kerning and Tracking list -100…200; a size, leading, kerning or tracking the selected text doesn't share shows blank (#458). Type › Bold and Italic (beyond Illustrator, as page layout apps have them; Cmd+Shift+B / Cmd+Shift+I while the Type tool edits text) switch the selected type to its family's own Bold or Italic face and back, keeping its width (a Narrow face stays Narrow); a family without that face says so (#724).
 - **Interface languages, vertical type:** Preferences ▸ User Interface (or VectorCraft ▸ Language on macOS) picks Automatic (the system locale) or a registered language, persisted as `interfaceLanguage`. Translations come from per-language catalogs (`i18n/*.tsv`): Traditional and Simplified Chinese, Japanese, German (every `de-*` locale), Spanish (neutral international Spanish, for every `es-*` locale), French (every `fr-*` locale), Italian (every `it-*` locale) Russian (every `ru-*` locale) and Ukrainian (every `uk-*` locale) cover the whole interface, Czech and Brazilian Portuguese every menu label, Brazilian Portuguese the shell's `tl!` literals too (tested); German, Spanish, French, Italian, Japanese, Russian and Ukrainian also translate status-bar and error messages as they are shown (`@msg` templates, every message literal tested; the messages themselves stay English for agents); untranslated text stays English. Japanese and Chinese glyphs come from the craft-fonts build input (release builds) or the installed fonts, Czech, German, Spanish, French, Italian, Russian and Ukrainian ones from the bundled UI fonts. The web app follows the browser's languages (or `?lang=`). The Basic toolbar's Type button holds Vertical Type in its flyout. Vertical Type, Vertical Area Type and Vertical Type on a Path create vertical text (columns right to left, upright CJK glyphs and marks with `vert` alternates, Latin and longer numbers on their side, two- and three-digit numbers set as tate-chu-yoko in one em of the column (kept whole when justified), upright glyphs centred on the column (tracked or justified too), point type's anchor on the first column's centre line); kinsoku applies to horizontal and vertical Japanese (Paragraph panel › Kinsoku Set, `text.setFormat {kinsoku}`: Hard, the default, keeps closing marks, iteration marks, the prolonged sound mark and small kana off the line start and opening brackets off its end; Soft lets 々, ー and small kana start a line as JLREQ's level 3 rules do; None turns it off), and justified Japanese lines spread their room between characters (not inside Latin words); Paragraph panel › Mojikumi Set (shown with Preferences › Type › Show East Asian Options, `text.setFormat {mojikumi}`): None or Line-end Punctuation Half Width (new type's default, as in Illustrator; older documents and imported text keep None) shares one half-em space between consecutive punctuation, sets a closing mark ending a line half width and an opening bracket starting a line flush with its start (a paragraph's first line at its first-line indent, JIS X 4051's principle in JLREQ 3.1.5), and puts a quarter em between Japanese and Latin letters or digits; Paragraph panel menu › Top-to-Top / Bottom-to-Bottom Leading measures leading from em box top to top (area type's first line touches the frame) or from baseline to baseline (new type in a Japanese interface starts top to top, with em box centre character alignment, #432); Paragraph panel menu › Burasagari None / Regular / Force (`text.setFormat {burasagari: "none"|"standard"|"forced"}`) hangs an East Asian comma or full stop (、。，．､｡) ending an area type line outside it, Regular (new type's default) when it doesn't fit and Force always (the rest of the line then fills the measure; closing brackets and Latin punctuation don't hang); Character panel menu › Character Alignment (with the East Asian options; `text.setFormat` or `text.setRangeStyle {charAlign}`) lines characters smaller than the largest on their line up on the Roman baseline, the em box top/right, centre or bottom/left, or the ICF (ideographic character face) top/right or bottom/left, from the font's BASE table or, without one, the average ink box of some ideographs and kana; Proportional Metrics (the same menu; `{proportionalMetrics}`) sets full-width glyphs on the font's proportional widths (OpenType `palt`) in horizontal type and upright glyphs on its proportional heights (`vpal`, shaped top to bottom; fonts without vertical metrics keep their cells) in vertical type, and Line-end Punctuation Half Width takes nothing more off the punctuation they re-spaced; Type ▸ Type Orientation switches existing text; caret, selection, hit testing and arrow keys follow the writing direction. Vertical text exports to PDF as real text and to SVG as outlines.
 - **Transparency:** opacity masks (clip/invert/disable/link), exported as SVG `<mask>` and PDF soft masks.
+  Disable, Enable, Unlink and Link Opacity Mask and Opacity Mask Options (`transparency.setOpacityMask`) record no undo step when every mask they act on already has the flags they set.
 - **Image Trace Flat Logo mode:** a fourth mode beside Black and White, Grayscale and Color, for flat-colour logos. Each pixel is read as a blend of the logo's colours (found automatically or named), the blend is interpolated smoothly and every outline is placed where two colours are equally present, so edges are accurate to a fraction of a pixel. Outlines are then cleaned: corners the blur rounded are put back, near-straight runs and near-circular arcs become exact lines and arcs, the rest is fitted with as few Béziers as the tolerance allows, touching colours overlap by a hair so no gap opens, and an outline that strays from the raw contour is fitted plainly instead. Gradients and photos are refused with advice to use Color. *Measured* (a local experiment, not run in CI): a flat-colour logo's vector original was rendered down to a soft 199 × 100 px transparent PNG, traced, and the result compared with the original at 1600 px wide. The built-in colour presets (6 Colors, 16 Colors, High Fidelity Photo, Low Fidelity Photo) had a mean edge error of 2.5 to 3.4 px and region overlap of 0.88 to 0.91; Flat Logo had 0.78 px and 0.966 (0.48 px and 0.975 from a crisp source), in about 0.1 s. Limits: flat-colour art only; needle-thin sharp tips are shortened by about 1.7 source pixels because the blur erases them; it works at no more than 1024 px on the long side (larger images are averaged down first); only one logo family has been scored against a vector original.
 - **Advanced art:** live Blends (steps/distance/smooth colour, editable spine, anchor-targeted Blend tool, faithful interpolation, knockout), Envelope Distort (warp/mesh/top object, Reset, full Envelope Options, mesh handles, Edit Contents; type, images, symbols, gradients, patterns and appearance distorted everywhere), Liquify tools with options and pen pressure, Puppet Warp with rotating pins, Perspective Grid with presets, movable planes and projected type (choosing a perspective tool shows the grid; Hide Grid hides it with the tool still chosen), Gradient Mesh, Shape Builder (stroke-only open paths and lines cut the regions they cross and enclose regions of their own, and regions they bound merge without seams where the lines cross at rounded coordinates (#893); filled open paths count as closed; erase mode while Alt/Option is held: a minus pointer, red highlights of what will go, a click or drag deletes the regions touched, the pieces of open lines and the edges (outline pieces between the points where paths meet, opening their paths there) it passes over, one undo step, `shapeBuilder.merge {erase}` and `shapeBuilder.regions` edges over MCP), Live Paint (every path an edge, open lines included), Image Trace (12 presets, colour layers traced in parallel; a trace past two million anchor points is refused with advice rather than running out of memory, an image over 64 megapixels is traced scaled down to that size (aspect kept, paths at the image's own size) and one over 192 megapixels is refused, and a selection too large to outline shows its bounds (#525); Object › Image Trace › Make and Make and Expand trace at once with the Default preset, #543; with an image selected the Control bar and the Properties panel show Image Trace, whose arrow traces with any preset, Mask (`object.maskImage`: a clipping path on the image's outline, selected so its handles crop), Crop Image (a crop box on the image, starting on its part over the artboard, dragged by its handles or inside it, the outside dimmed, with X/Y/W/H, Apply and Cancel in the Control bar, Enter and Escape, #734; `object.cropImage {rect}` for agents, `{trim: true}` cuts an image to its pixels that aren't fully transparent, pixel for pixel) and Embed or Unembed in place of Fill and Stroke; with an Image Trace object selected, its Preset (choosing another traces again), View, the Image Trace panel and Expand, plus Release in Properties; the five View modes (Tracing Result, with Outlines, Outlines, Outlines with Source Image, Source Image) redraw a trace on screen without tracing again, are saved with it and `imageTrace.setView` sets them, while exports and Expand keep the result; the panel's Advanced section is a header that stays open or closed as it was left (part of #641); Color mode's Palette: Limited, Full Tone (as many colours as the tones need, Less … More), Automatic (flat art with its own colours, else Full Tone; a heuristic) and Document Library (the most used colours of the document's swatches or a swatch library, filled with the swatch colours as they are), part of #641; Advanced › Create: Fills and/or Strokes, where lines up to the Stroke width trace as stroked centre lines (distance transform, thinning, a skeleton graph with spurs pruned, curve fitting; one width per line; without Fills, wider areas become stroked outlines), part of #641), pattern swatches with pattern editing mode, live Repeat (radial/grid/mirror).
 - **Paint and appearance (M3):**