diff --git a/ROADMAP.md b/ROADMAP.md
index 5b1c0b75..66983a40 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -4,7 +4,7 @@ VectorCraft is a clean-room, open-source, pure-Rust reimplementation of the Adob
 
 This file tracks **how far we are and what's left**. Time estimates are wall-clock hours of continuous Claude Opus 5.5 agent work (including builds and the CI gate), given both for **one agent** and for **4–6 parallel agents** on disjoint crates. They are counted from the remaining work (see [Parity estimate](#parity-estimate)), calibrated against measured throughput, and updated as work lands.
 
-_Last updated: 2026-10-09 (after placed documents (File › Place of a `.vectorcraft` file, linked), M4.14–M4.98, M8.1–M8.20, M14.4–M14.7, the MCP prompts, resource templates, completions and logging, the 2026-10-07 issue fixes, the Layers panel rework and the 2026-10-08 community contributions: Pen and shape-tool modifiers, path editing, Layers, Artboards, Swatches/Brushes and dialogs, Japanese composition and PDF text, Hebrew/Arabic type, interface languages (Spanish among them), the font menu, saved selections, MCP and EPS, the missing-font export warning (#319), open paths in the Shape Builder (#374), PDF/`.ai` import keeping strokes live and hidden and nested layers (#372), per-corner Live Corners (#381), SVG type opening at the size it draws at (#396), the Wayland clipboard with copied-file paste (#398), ruler guides that can be selected, moved and deleted (#414), two batches of Preferences options that were stored but unused (#394), skeleton reads with `document.find` for large documents over MCP (#416) and anchors dragged with Direct Selection snapping to points, segments and smart guides, clipped SVG layers opening as clipping layers (#420), PDF/`.ai` layers read on pages of tens of millions of operators (#419), Document Color Mode putting RGB greys on the black plate on request and converting pattern tiles (#421) and movable dialogs with Offset Path's Joins dropdown (#423) and numeric fields scrubbed by dragging their label (#400), stroke weight presets in the stroke unit (#426), the Appearance panel's Opacity popup (#430), type on a path brackets, flip and Type on a Path Options that keep the type in place (#429), Layers rows dragged with a ghost and dropped on the trash or New Layer (#435), tool flyouts opening on a right or corner press (#436), tool flyouts torn off into floating toolbars (#437), the Shape Builder's erase mode deleting edges too (#439), installed fonts registered outside the font folders and fonts installed while the app runs listed in the font menus (#443), alike circular corners on rectangles that aren't square (#442), tool cursors as OS cursors so the pointer no longer trails over the canvas (#444), artboards copied and pasted with their art (#446), guides dragged out of the rulers snapping to the art's side midpoints and the artboards, artboard guides (#451), the toolbar's double arrow and Window › Toolbars › Double Column switching between one and two columns in any window height (#455), the Smart Guides display options and Snapping Tolerance (#394), Font Size and Leading combo boxes with preset lists in the Character and Properties panels and the Control bar (#458), screenshots pasted from the clipboard on macOS, Windows and the web (#457), the Properties panel's Fill and Stroke matching the Control bar's, Illustrator's Window menu panel keys (Shift+F7 for Align…) and Alt-wheel zoom whatever the wheel preference (Discord feedback), the point/area type widget (Discord feedback), groups in legacy Illustrator .ai files (Discord feedback), a rotating desktop log file (#465), image controls in the Control bar and Properties panel: Image Trace with its presets, Mask, Crop Image, Embed/Unembed, and an Image Trace object's preset, Expand and Release (Discord feedback), the Pen working as the Anchor Point tool with Alt held over a selected path's handles and anchors, and anchor buttons that convert, connect and cut paths at the selected anchors (Discord feedback), Japanese hanging punctuation (burasagari, #463), Escape leaving Presentation Mode with no screen mode saved across restarts, documents dropped on the desktop app opening as tabs of their own and a note that an `.ai` file's art off its artboards isn't in the part read (#472), Add/Delete Anchor Point tool icons drawn from the Pen tool's (#479), EPS import running more of PostScript Level 3 (patterns, Type 3 fonts, mesh shadings, masked images, VM and resource probes), and a preview that stands in saying why (Discord feedback, #466, #469, #474), chords with modifiers recorded in Edit › Keyboard Shortcuts (#487), Type Object Selection by Path Only (#394), Anti-aliased Artwork (#394), Show Pixel Grid (#394), pen and touch taps pressed and lifted within one frame clicking where they tapped and the Linux/Wayland pen-tablet workaround (#491), bounding-box resizes landing on the other objects' anchors and centres with labels, and the Rotate, Scale, Shear and Reflect tools snapping their drags (#482), Shift-drag marquees that toggle the objects or anchors they reach and a Lasso whose Alt subtraction keeps the rest of the selection (#483), the mouse wheel stepping the focused numeric field, the dialogs' and preferences' drag values made such fields (#485), Show The Home Screen When No Documents Are Open (#394), Numbers Without Units Are Points (#394), Auto-Collapse Iconic Panels (#394), the Contextual Task Bar moved by its handle and its More Options menu pinning and resetting its position, a designed macOS DMG window (#493), panels, panel groups and the Tools panel undocking into floating panels that move, stack and dock again (#495), the 0.5.0 startup crash on dual-GPU Linux desktops under Wayland fixed: the desktop's own GPU by default and a restart on the next GPU when one can't show the window (#502), path editing while drawing: Cmd/Ctrl with the Pen borrowing Direct Selection and drawing on afterwards, Pen+Alt reshaping segments, handles of a whole selected path dragging, and handle drags no longer re-gathering snap targets every move (#494), the Control bar's and Properties panel's Convert buttons for a path selected as a whole with Direct Selection, the Pen and the anchor tools (#504), the Pen closing a path dragged out of its first anchor every time, without flicker (#501), the Paste menu checking the system clipboard on a background thread on Linux so an X11 clipboard owner that never answers no longer freezes the window (#510), PDF/`.ai` import keeping a type object's outline stroke on the type, wrapped lines as area type, barcode digits in place and layers in the file's stacking order (#508), the Italian interface (#514), EPS images with several data sources read in turn (#498), `restore` undoing dictionary changes in EPS import (part of #505), the macOS menu bar laid out as a Mac app's (the VectorCraft menu with Settings, Language and Appearance, the system's Hide, Services and Window items; owner's request), Object › Image Trace › Make tracing with the Default preset instead of asking for a preset's name (#543), the rulers' unit menu (#528), Live Corners on stars, polygons and pen paths (#511), the drawing tools snapping to Smart Guides as the Selection tool does, with Construction Guides (#506), the in-window menus' Select All, Cut, Copy and Paste acting on the text field they were opened from (#516), Windows rendering through DX12 before Vulkan (#545), Image Trace tracing colour layers in parallel and refusing traces too large for memory, with the canvas outlining huge selections by their bounds (#525), SVGs of chosen artboards holding only the art over each artboard (#550), the font menu scrolling only its list, under a search field and filters that stay put (#555), a click on an object of a selection making it the key object that Align aligns to and Distribute Spacing spaces from, drawn with a thicker outline (#541), Shape Builder merges taken from the planar map itself, so merged regions leave no inner edge, hairline gap or spur in their outline (#569), `.ai` written by the exports and the CLI (`--export`, `convert`) as Save As writes it (#526), SVG round trips keeping hidden objects and `data-*` attributes (#522), the gradient stop popover staying open after the click that opens it from the Gradient panel (#577), standard ligatures kept under small tracking and dropped only past about −8% / +22% of a word space or when the character asks for them (#583), the Color panel keeping its height as warnings come and go so a drag on its spectrum no longer flickers near white (#578), fonts that font services such as Adobe Fonts load on Windows, listed through DirectWrite (#579); see [Honest assessment](#honest-assessment-2026-10-05))._
+_Last updated: 2026-10-09 (after placed documents (File › Place of a `.vectorcraft` file, linked), M4.14–M4.98, M8.1–M8.20, M14.4–M14.7, the MCP prompts, resource templates, completions and logging, the 2026-10-07 issue fixes, the Layers panel rework and the 2026-10-08 community contributions: Pen and shape-tool modifiers, path editing, Layers, Artboards, Swatches/Brushes and dialogs, Japanese composition and PDF text, Hebrew/Arabic type, interface languages (Spanish among them), the font menu, saved selections, MCP and EPS, the missing-font export warning (#319), open paths in the Shape Builder (#374), PDF/`.ai` import keeping strokes live and hidden and nested layers (#372), per-corner Live Corners (#381), SVG type opening at the size it draws at (#396), the Wayland clipboard with copied-file paste (#398), ruler guides that can be selected, moved and deleted (#414), two batches of Preferences options that were stored but unused (#394), skeleton reads with `document.find` for large documents over MCP (#416) and anchors dragged with Direct Selection snapping to points, segments and smart guides, clipped SVG layers opening as clipping layers (#420), PDF/`.ai` layers read on pages of tens of millions of operators (#419), Document Color Mode putting RGB greys on the black plate on request and converting pattern tiles (#421) and movable dialogs with Offset Path's Joins dropdown (#423) and numeric fields scrubbed by dragging their label (#400), stroke weight presets in the stroke unit (#426), the Appearance panel's Opacity popup (#430), type on a path brackets, flip and Type on a Path Options that keep the type in place (#429), Layers rows dragged with a ghost and dropped on the trash or New Layer (#435), tool flyouts opening on a right or corner press (#436), tool flyouts torn off into floating toolbars (#437), the Shape Builder's erase mode deleting edges too (#439), installed fonts registered outside the font folders and fonts installed while the app runs listed in the font menus (#443), alike circular corners on rectangles that aren't square (#442), tool cursors as OS cursors so the pointer no longer trails over the canvas (#444), artboards copied and pasted with their art (#446), guides dragged out of the rulers snapping to the art's side midpoints and the artboards, artboard guides (#451), the toolbar's double arrow and Window › Toolbars › Double Column switching between one and two columns in any window height (#455), the Smart Guides display options and Snapping Tolerance (#394), Font Size and Leading combo boxes with preset lists in the Character and Properties panels and the Control bar (#458), screenshots pasted from the clipboard on macOS, Windows and the web (#457), the Properties panel's Fill and Stroke matching the Control bar's, Illustrator's Window menu panel keys (Shift+F7 for Align…) and Alt-wheel zoom whatever the wheel preference (Discord feedback), the point/area type widget (Discord feedback), groups in legacy Illustrator .ai files (Discord feedback), a rotating desktop log file (#465), image controls in the Control bar and Properties panel: Image Trace with its presets, Mask, Crop Image, Embed/Unembed, and an Image Trace object's preset, Expand and Release (Discord feedback), the Pen working as the Anchor Point tool with Alt held over a selected path's handles and anchors, and anchor buttons that convert, connect and cut paths at the selected anchors (Discord feedback), Japanese hanging punctuation (burasagari, #463), Escape leaving Presentation Mode with no screen mode saved across restarts, documents dropped on the desktop app opening as tabs of their own and a note that an `.ai` file's art off its artboards isn't in the part read (#472), Add/Delete Anchor Point tool icons drawn from the Pen tool's (#479), EPS import running more of PostScript Level 3 (patterns, Type 3 fonts, mesh shadings, masked images, VM and resource probes), and a preview that stands in saying why (Discord feedback, #466, #469, #474), chords with modifiers recorded in Edit › Keyboard Shortcuts (#487), Type Object Selection by Path Only (#394), Anti-aliased Artwork (#394), Show Pixel Grid (#394), pen and touch taps pressed and lifted within one frame clicking where they tapped and the Linux/Wayland pen-tablet workaround (#491), bounding-box resizes landing on the other objects' anchors and centres with labels, and the Rotate, Scale, Shear and Reflect tools snapping their drags (#482), Shift-drag marquees that toggle the objects or anchors they reach and a Lasso whose Alt subtraction keeps the rest of the selection (#483), the mouse wheel stepping the focused numeric field, the dialogs' and preferences' drag values made such fields (#485), Show The Home Screen When No Documents Are Open (#394), Numbers Without Units Are Points (#394), Auto-Collapse Iconic Panels (#394), the Contextual Task Bar moved by its handle and its More Options menu pinning and resetting its position, a designed macOS DMG window (#493), panels, panel groups and the Tools panel undocking into floating panels that move, stack and dock again (#495), the 0.5.0 startup crash on dual-GPU Linux desktops under Wayland fixed: the desktop's own GPU by default and a restart on the next GPU when one can't show the window (#502), path editing while drawing: Cmd/Ctrl with the Pen borrowing Direct Selection and drawing on afterwards, Pen+Alt reshaping segments, handles of a whole selected path dragging, and handle drags no longer re-gathering snap targets every move (#494), the Control bar's and Properties panel's Convert buttons for a path selected as a whole with Direct Selection, the Pen and the anchor tools (#504), the Pen closing a path dragged out of its first anchor every time, without flicker (#501), the Paste menu checking the system clipboard on a background thread on Linux so an X11 clipboard owner that never answers no longer freezes the window (#510), PDF/`.ai` import keeping a type object's outline stroke on the type, wrapped lines as area type, barcode digits in place and layers in the file's stacking order (#508), the Italian interface (#514), EPS images with several data sources read in turn (#498), `restore` undoing dictionary changes in EPS import (part of #505), the macOS menu bar laid out as a Mac app's (the VectorCraft menu with Settings, Language and Appearance, the system's Hide, Services and Window items; owner's request), Object › Image Trace › Make tracing with the Default preset instead of asking for a preset's name (#543), the rulers' unit menu (#528), Live Corners on stars, polygons and pen paths (#511), the drawing tools snapping to Smart Guides as the Selection tool does, with Construction Guides (#506), the in-window menus' Select All, Cut, Copy and Paste acting on the text field they were opened from (#516), Windows rendering through DX12 before Vulkan (#545), Image Trace tracing colour layers in parallel and refusing traces too large for memory, with the canvas outlining huge selections by their bounds (#525), SVGs of chosen artboards holding only the art over each artboard (#550), the font menu scrolling only its list, under a search field and filters that stay put (#555), a click on an object of a selection making it the key object that Align aligns to and Distribute Spacing spaces from, drawn with a thicker outline (#541), Shape Builder merges taken from the planar map itself, so merged regions leave no inner edge, hairline gap or spur in their outline (#569), `.ai` written by the exports and the CLI (`--export`, `convert`) as Save As writes it (#526), SVG round trips keeping hidden objects and `data-*` attributes (#522), the gradient stop popover staying open after the click that opens it from the Gradient panel (#577), standard ligatures kept under small tracking and dropped only past about −8% / +22% of a word space or when the character asks for them (#583), the Color panel keeping its height as warnings come and go so a drag on its spectrum no longer flickers near white (#578), fonts that font services such as Adobe Fonts load on Windows, listed through DirectWrite (#579), `.ai` files writing their layers and sublayers as PDF layers, hidden ones with their art, and PDF layers nested in layers importing as sublayers (#372); see [Honest assessment](#honest-assessment-2026-10-05))._
 
 ## Where we are
 
diff --git a/crates/engine/src/cmd/fileio/pdf.rs b/crates/engine/src/cmd/fileio/pdf.rs
index 409e5847..e02ad9ac 100644
--- a/crates/engine/src/cmd/fileio/pdf.rs
+++ b/crates/engine/src/cmd/fileio/pdf.rs
@@ -86,7 +86,7 @@ pub(super) const OPTIONS: &[FormatOption] = &[
         name: "createLayers",
         ty: "boolean",
         default: "false",
-        description: "top-level layers as PDF layers (optional content groups with their visibility, print state and lock; PDF 1.5 or later)",
+        description: "layers and sublayers as PDF layers (optional content groups with their visibility, print state and lock, sublayers listed under their layers; PDF 1.5 or later)",
     },
     FormatOption {
         name: "flattenerPreset",
@@ -109,7 +109,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Export PDF",
             [],
             None,
-            "{path?, preset?: \"VectorCraft Default\" (built-in or saved: pdf.preset.list), artboard? | artboards?: [i…] | range?: \"1-3, 5\" (1-based; default all, one page each), standard?: none|pdfA2b|pdfX1a (CMYK, grey and spot colours only: colours and images converted to output.destination or the CMYK output intent, untagged; transparency flattened with flattenerPreset; PDF 1.3)|pdfX3 (colours ICC-tagged; transparency flattened; PDF 1.3)|pdfX4 (transparency and layers kept; colours ICC-tagged; PDF 1.6 at most) (PDF/X: a /GTS_PDFX output intent, by default the CMYK profile in effect, embedded; TrimBox, Trapped, GTS_PDFXVersion, title and dates; fonts embedded or outlined), compatibility?: 1.3 (no transparency: it is flattened with flattenerPreset; images keep no see-through pixels)|1.4|1.5|1.6|1.7 (default)|2.0 (choosing a standard sets its version: 1.7 for pdfA2b, 1.6 for pdfX4, 1.3 for pdfX1a and pdfX3, which write 1.4 as 1.3 too; pdfA2b refuses 1.3), preserveEditing? (on in VectorCraft Default: the native document as an embedded file, which document.open restores; choosing a standard turns it off, a standard refuses it), thumbnails? (each page drawn as a /Thumb image, 106 px on its long side), fastWebView? (a linearised file: the first page shows while the rest downloads; it stays linearised when encrypted), viewAfterSaving? (the app opens the written file), createLayers? (each top-level layer but template layers as a PDF layer, an optional content group: hidden layers off, non-printing ones /PrintState /OFF, locked ones locked; needs 1.5 or later; they reopen as layers; choosing pdfX1a or pdfX3 turns it off; they refuse it), includeNonPrinting? (keep layers whose Print option is off; left out by default unless createLayers), flattenerPreset?: \"\" (High Resolution) | high | medium | low | a saved preset (flattener.presets.list): what PDF 1.3 files flatten transparency with, flattener?: {object.flattenTransparency options over it}, compression?: {color?, gray?: {downsample: none|average|subsample|bicubic, ppi: 300, abovePpi: 450, compression: none|zip|jpeg|jpeg2000|auto, quality: minimum|low|medium|high|maximum}, mono?: {downsample, ppi: 1200, abovePpi: 1800, compression: none|ccittG3|ccittG4|zip|runLength} (black-and-white images), compressText?: true} (images above abovePpi are resampled to ppi; auto keeps JPEGs JPEG, the others lossless; JPEG needs opaque images; none, jpeg2000, CCITT and runLength are written as ZIP with a warning), marks?: {trim, registration, colorBars, pageInfo, kind: roman|japanese, weight: 0.25 (trim marks and targets), offset: 6 (pt from the artboard, at least the bleed)} (printer's marks in [Registration], every plate: trim marks, registration targets mid-side, CMYK/spot/black-tint colour bars on top, page information (title, artboard, date UTC) below), bleed?: {useDocument (the document's bleed, document.setup), top, bottom, left, right} (pt; art in the bleed is kept). Each page: TrimBox = artboard, BleedBox = artboard + bleed, MediaBox = that + the marks' room (art clipped to the BleedBox), output?: {conversion: none (default)|destination (every colour into the destination profile's model, CMYK or RGB, also colours of that model in another profile)|preserveNumbers (only colours of the other model and Lab; those in the destination's model keep their numbers) (grey stays grey; images are converted too, printer's marks are not), destination: profile name (edit.colorSettings lists them; default: the document's profile for its colour mode), profiles: none (device colours)|all|destination|taggedSource (documents assigned a profile: edit.assignProfile) (ICC-based colours: CMYK with the destination or document CMYK profile, RGB as sRGB, grey with the sRGB tone curve; PDF/A always), outputIntent: profile name (embedded as the catalog's /GTS_PDFX output intent; a name that isn't a profile is only named, which pdfX1a and pdfX3 allow only with a registry and pdfX4 refuses; pdfX1a needs a CMYK one), outputCondition, outputConditionId (default: outputIntent), registry, trapped (/Trapped /True; /False when an output intent is written)} (PDF/A files keep their own output intent), advanced?: {fontSubsetPercent: 100 (below 100 is accepted with a warning: fonts are always embedded as subsets), outlineText: true (false: type as real, selectable and searchable text in embedded subset fonts with a ToUnicode map; fonts whose licence forbids embedding, or allows only whole fonts, stay outlines with a warning), overprint: preserve (overprinting fills and strokes set /OP /op true, /OPM 1; white ones knock out with document.setup discardWhiteOverprint)|discard (they knock out)}, security?: {openPassword, permissionsPassword, printing: none|low|high, changes: none|pages|forms|comments|any, copy, screenReader, plaintextMetadata}} → {path, bytes, warnings}; no path → {dataBase64, bytes, warnings}. The options apply over the preset (null keeps its value); options accepted but not applied yet come back as warnings; a standard with a PDF version it doesn't allow and a password with a standard are refused, and so is a PDF/X file that would still break its standard (transparency the flattener left, RGB in pdfX1a, a font not embedded) or a PDF 1.3 file with transparency left. document.export {format: pdf} takes the same options",
+            "{path?, preset?: \"VectorCraft Default\" (built-in or saved: pdf.preset.list), artboard? | artboards?: [i…] | range?: \"1-3, 5\" (1-based; default all, one page each), standard?: none|pdfA2b|pdfX1a (CMYK, grey and spot colours only: colours and images converted to output.destination or the CMYK output intent, untagged; transparency flattened with flattenerPreset; PDF 1.3)|pdfX3 (colours ICC-tagged; transparency flattened; PDF 1.3)|pdfX4 (transparency and layers kept; colours ICC-tagged; PDF 1.6 at most) (PDF/X: a /GTS_PDFX output intent, by default the CMYK profile in effect, embedded; TrimBox, Trapped, GTS_PDFXVersion, title and dates; fonts embedded or outlined), compatibility?: 1.3 (no transparency: it is flattened with flattenerPreset; images keep no see-through pixels)|1.4|1.5|1.6|1.7 (default)|2.0 (choosing a standard sets its version: 1.7 for pdfA2b, 1.6 for pdfX4, 1.3 for pdfX1a and pdfX3, which write 1.4 as 1.3 too; pdfA2b refuses 1.3), preserveEditing? (on in VectorCraft Default: the native document as an embedded file, which document.open restores; choosing a standard turns it off, a standard refuses it), thumbnails? (each page drawn as a /Thumb image, 106 px on its long side), fastWebView? (a linearised file: the first page shows while the rest downloads; it stays linearised when encrypted), viewAfterSaving? (the app opens the written file), createLayers? (each layer and sublayer but template layers as a PDF layer, an optional content group listed under its layer's: hidden layers off, non-printing ones /PrintState /OFF, locked ones locked; needs 1.5 or later; they reopen as layers; choosing pdfX1a or pdfX3 turns it off; they refuse it), includeNonPrinting? (keep layers whose Print option is off; left out by default unless createLayers), flattenerPreset?: \"\" (High Resolution) | high | medium | low | a saved preset (flattener.presets.list): what PDF 1.3 files flatten transparency with, flattener?: {object.flattenTransparency options over it}, compression?: {color?, gray?: {downsample: none|average|subsample|bicubic, ppi: 300, abovePpi: 450, compression: none|zip|jpeg|jpeg2000|auto, quality: minimum|low|medium|high|maximum}, mono?: {downsample, ppi: 1200, abovePpi: 1800, compression: none|ccittG3|ccittG4|zip|runLength} (black-and-white images), compressText?: true} (images above abovePpi are resampled to ppi; auto keeps JPEGs JPEG, the others lossless; JPEG needs opaque images; none, jpeg2000, CCITT and runLength are written as ZIP with a warning), marks?: {trim, registration, colorBars, pageInfo, kind: roman|japanese, weight: 0.25 (trim marks and targets), offset: 6 (pt from the artboard, at least the bleed)} (printer's marks in [Registration], every plate: trim marks, registration targets mid-side, CMYK/spot/black-tint colour bars on top, page information (title, artboard, date UTC) below), bleed?: {useDocument (the document's bleed, document.setup), top, bottom, left, right} (pt; art in the bleed is kept). Each page: TrimBox = artboard, BleedBox = artboard + bleed, MediaBox = that + the marks' room (art clipped to the BleedBox), output?: {conversion: none (default)|destination (every colour into the destination profile's model, CMYK or RGB, also colours of that model in another profile)|preserveNumbers (only colours of the other model and Lab; those in the destination's model keep their numbers) (grey stays grey; images are converted too, printer's marks are not), destination: profile name (edit.colorSettings lists them; default: the document's profile for its colour mode), profiles: none (device colours)|all|destination|taggedSource (documents assigned a profile: edit.assignProfile) (ICC-based colours: CMYK with the destination or document CMYK profile, RGB as sRGB, grey with the sRGB tone curve; PDF/A always), outputIntent: profile name (embedded as the catalog's /GTS_PDFX output intent; a name that isn't a profile is only named, which pdfX1a and pdfX3 allow only with a registry and pdfX4 refuses; pdfX1a needs a CMYK one), outputCondition, outputConditionId (default: outputIntent), registry, trapped (/Trapped /True; /False when an output intent is written)} (PDF/A files keep their own output intent), advanced?: {fontSubsetPercent: 100 (below 100 is accepted with a warning: fonts are always embedded as subsets), outlineText: true (false: type as real, selectable and searchable text in embedded subset fonts with a ToUnicode map; fonts whose licence forbids embedding, or allows only whole fonts, stay outlines with a warning), overprint: preserve (overprinting fills and strokes set /OP /op true, /OPM 1; white ones knock out with document.setup discardWhiteOverprint)|discard (they knock out)}, security?: {openPassword, permissionsPassword, printing: none|low|high, changes: none|pages|forms|comments|any, copy, screenReader, plaintextMetadata}} → {path, bytes, warnings}; no path → {dataBase64, bytes, warnings}. The options apply over the preset (null keeps its value); options accepted but not applied yet come back as warnings; a standard with a PDF version it doesn't allow and a password with a standard are refused, and so is a PDF/X file that would still break its standard (transparency the flattener left, RGB in pdfX1a, a font not embedded) or a PDF 1.3 file with transparency left. document.export {format: pdf} takes the same options",
             has_doc,
             export_pdf
         ),
diff --git a/crates/engine/src/cmd/fileio/save.rs b/crates/engine/src/cmd/fileio/save.rs
index c20dbe7e..0f9d29e7 100644
--- a/crates/engine/src/cmd/fileio/save.rs
+++ b/crates/engine/src/cmd/fileio/save.rs
@@ -306,11 +306,16 @@ fn blank_pages(doc: &Document) -> Document {
 const NOT_PDF_COMPATIBLE: &str = "saved without PDF content: VectorCraft opens it as before, other apps show empty pages";
 
 /// The encoder's params for a `.ai` file, from a save's or an export's: a PDF of every artboard
-/// with the PDF options, always carrying the native document; Use Compression compresses the
-/// PDF's content.
+/// with the PDF options, always carrying the native document, its layers and sublayers PDF layers
+/// (hidden ones off) unless asked otherwise; Use Compression compresses the PDF's content.
 pub(super) fn ai_params(params: &mut Value) {
     let Some(o) = params.as_object_mut() else { return };
     o.extend([("preserveEditing".into(), json!(true)), ("range".into(), json!("all"))]);
+    // Apps that read the PDF part (not the native document) then find the layers, the hidden ones
+    // with their art (#372); a PDF standard decides for itself.
+    if o.get("standard").is_none_or(Value::is_null) {
+        o.entry("createLayers").or_insert(json!(true));
+    }
     if let Some(c) = o.get("compress").and_then(Value::as_bool) {
         let compression = o.entry("compression").or_insert_with(|| json!({}));
         if let Some(m) = compression.as_object_mut() {
diff --git a/crates/engine/src/cmd/fileio/tests_pdflayers.rs b/crates/engine/src/cmd/fileio/tests_pdflayers.rs
index 7576bc61..a1e71a9e 100644
--- a/crates/engine/src/cmd/fileio/tests_pdflayers.rs
+++ b/crates/engine/src/cmd/fileio/tests_pdflayers.rs
@@ -59,3 +59,35 @@ fn export_pdf_overprint_is_preserved_or_discarded() {
     assert_eq!(overprints(&mut s, json!({"compression": {"compressText": false}})), 1);
     assert_eq!(overprints(&mut s, json!({"advanced": {"overprint": "discard"}})), 0);
 }
+
+/// A `.ai` file's PDF part, which apps that don't read the native document open, has the layers
+/// and sublayers as PDF layers, the hidden ones with their art (#372).
+#[test]
+fn ai_files_write_their_layers_and_sublayers_as_pdf_layers() {
+    let mut s = session();
+    let layer1 = s.execute("document.inspect", &json!({})).unwrap()["layers"][1]["id"].as_u64().unwrap();
+    let sub = s.execute("layer.newSublayer", &json!({"parent": layer1, "name": "Sketch"})).unwrap()["id"].as_u64().unwrap();
+    s.execute("layer.setCurrent", &json!({"id": sub})).unwrap();
+    s.execute("shape.ellipse", &json!({"x": 10, "y": 40, "width": 20, "height": 20})).unwrap();
+    s.execute("layer.setProps", &json!({"id": sub, "visible": false})).unwrap();
+    // Name, shown and what it holds (sublayers by name), top-level layers in paint order.
+    fn rows(layers: &[std::sync::Arc<vectorcraft_doc::Node>]) -> Vec<(String, bool, Vec<String>)> {
+        layers
+            .iter()
+            .map(|l| {
+                let held =
+                    l.children().into_iter().flatten().map(|c| c.name.clone().filter(|_| c.is_layer()).unwrap_or_else(|| "art".into())).collect();
+                (l.name.clone().unwrap_or_default(), l.visible, held)
+            })
+            .collect()
+    }
+    let v = s.execute("document.export", &json!({"format": "ai"})).unwrap();
+    let back = vectorcraft_pdf::import(&b64(&v)).unwrap();
+    let art = || "art".to_string();
+    assert_eq!(rows(&back.layers), [("Layer 1".to_string(), true, vec![art(), "Sketch".into()]), ("Notes".to_string(), false, vec![art()])]);
+    let sketch = back.layers.first().and_then(|l| l.children()?.last().cloned()).unwrap();
+    assert_eq!(rows(&[sketch]), [("Sketch".to_string(), false, vec![art()])]);
+    // Asked not to, it writes none.
+    let v = s.execute("document.export", &json!({"format": "ai", "createLayers": false})).unwrap();
+    assert_eq!(vectorcraft_pdf::import(&b64(&v)).unwrap().layers.len(), 1);
+}
diff --git a/crates/pdf/src/export.rs b/crates/pdf/src/export.rs
index 548c33b9..9390cdc4 100644
--- a/crates/pdf/src/export.rs
+++ b/crates/pdf/src/export.rs
@@ -453,11 +453,13 @@ pub(crate) struct Exporter<'a> {
     /// The fonts real text is written in, by face id, with their units per em; `None` for faces
     /// that can't be embedded.
     fonts: HashMap<u32, Option<(krilla::text::Font, f64)>>,
-    /// Top-level layers are drawn as forms marked for their optional content groups
+    /// Layers and sublayers are drawn as forms marked for their optional content groups
     /// ([`crate::forms`]).
     pub layers: bool,
-    /// A top-level layer's form is being drawn.
-    in_layer: bool,
+    /// Each layer's index in [`crate::forms::pdf_layers`], by address.
+    layer_index: HashMap<usize, usize>,
+    /// The address of the layer whose form is being drawn.
+    in_layer: usize,
     /// Overprinting fills and strokes are drawn as forms marked to overprint.
     pub overprint: bool,
     /// An overprinting fill or stroke was drawn so.
@@ -485,7 +487,8 @@ impl<'a> Exporter<'a> {
             outline_text: set.advanced.outline_text,
             fonts: HashMap::new(),
             layers: false,
-            in_layer: false,
+            layer_index: crate::forms::pdf_layers(doc).iter().enumerate().map(|(i, l)| (address(l.node), i)).collect(),
+            in_layer: 0,
             overprint: false,
             overprinted: false,
         }
@@ -601,6 +604,11 @@ fn constant_mask(s: &mut Surface, page: Rect, alpha: f32) -> krilla::mask::Mask
     krilla::mask::Mask::new(sb.finish(), krilla::mask::MaskType::Alpha)
 }
 
+/// A node's address, to tell the very node apart from equal ones.
+fn address(n: &Node) -> usize {
+    std::ptr::from_ref(n).addr()
+}
+
 fn rects_overlap(a: Rect, b: Rect) -> bool {
     a.x0 <= b.x1 && b.x0 <= a.x1 && a.y0 <= b.y1 && b.y0 <= a.y1
 }
@@ -885,15 +893,15 @@ impl Exporter<'_> {
 
     fn node(&mut self, s: &mut Surface, n: &Node, page: Rect, force: bool) {
         if self.layers
-            && !self.in_layer
-            && let NodeKind::Layer { template: false, printable, .. } = n.kind
+            && self.in_layer != address(n)
+            && let NodeKind::Layer { printable, .. } = n.kind
             && (printable || self.non_printing)
-            && let Some(i) = self.doc.layers.iter().position(|l| std::ptr::eq(&**l, n))
+            && let Some(&i) = self.layer_index.get(&address(n))
         {
-            // A PDF layer: hidden layers are written too (their group is off).
-            self.in_layer = true;
+            // A PDF layer: hidden layers and sublayers are written too (their group is off).
+            let enclosing = std::mem::replace(&mut self.in_layer, address(n));
             crate::forms::form(s, Mark::Layer(i), |s| self.node(s, n, page, true));
-            self.in_layer = false;
+            self.in_layer = enclosing;
             return;
         }
         if !force && !n.visible {
diff --git a/crates/pdf/src/forms.rs b/crates/pdf/src/forms.rs
index b0730e78..60b91b33 100644
--- a/crates/pdf/src/forms.rs
+++ b/crates/pdf/src/forms.rs
@@ -11,7 +11,9 @@ use std::io::Read;
 use krilla::geom::PathBuilder;
 use krilla::graphic::Graphic;
 use krilla::surface::Surface;
-use vectorcraft_doc::{Document, NodeKind};
+use std::sync::Arc;
+
+use vectorcraft_doc::{Document, Node, NodeKind};
 
 use crate::encrypt::{Lexer, Obj, StreamSpans, Tok, int, stream_spans};
 use crate::output::{deflate, text_string};
@@ -21,12 +23,36 @@ use crate::{PdfError, PdfSettings, Standard};
 /// What a marked form is.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub(crate) enum Mark {
-    /// The art of top-level layer `i` (`Document::layers`).
+    /// The art of layer `i` of [`pdf_layers`].
     Layer(usize),
     /// A fill or stroke that overprints.
     Overprint,
 }
 
+/// A layer written as a PDF layer (an optional content group).
+pub(crate) struct PdfLayer<'a> {
+    pub node: &'a Node,
+    /// Its parent layer's index in [`pdf_layers`] (none for a top-level layer).
+    pub parent: Option<usize>,
+}
+
+/// The layers written as PDF layers: the top-level layers and their sublayers, but template layers
+/// (and what they hold), each before its sublayers, in paint order (bottom first).
+pub(crate) fn pdf_layers(doc: &Document) -> Vec<PdfLayer<'_>> {
+    fn add<'a>(nodes: &'a [Arc<Node>], parent: Option<usize>, out: &mut Vec<PdfLayer<'a>>) {
+        for n in nodes {
+            if let NodeKind::Layer { template: false, children, .. } = &n.kind {
+                let i = out.len();
+                out.push(PdfLayer { node: n, parent });
+                add(children, Some(i), out);
+            }
+        }
+    }
+    let mut out = vec![];
+    add(&doc.layers, None, &mut out);
+    out
+}
+
 /// The x coordinate of a layer mark's first point (its y is the layer index).
 const LAYER_X: i32 = -32000;
 /// The x coordinate of an overprint mark's first point.
@@ -199,7 +225,7 @@ fn mark_layers(content: &[u8], forms: &HashMap<&[u8], usize>) -> Option<(Vec<u8>
 }
 
 /// Finish the marked forms of `pdf` (as [`crate::export`] writes `doc` with `set`): with
-/// `layers`, each top-level layer (but template layers) becomes an optional content group —
+/// `layers`, each layer and sublayer (but template layers) becomes an optional content group —
 /// named as the layer, off when it is hidden, not printed (`/PrintState /OFF`) when its Print
 /// option is off, locked when it is locked — and the uses of its forms its optional content;
 /// with `overprint`, the overprinting forms get a graphics state that overprints (`/OP`, `/op`,
@@ -228,6 +254,11 @@ pub(crate) fn finish(pdf: Vec<u8>, doc: &Document, set: &PdfSettings, layers: bo
     }
     if layers {
         write_layers(&pdf, &xref, &objects, &marks, &mut patch, doc, set)?;
+        for (n, _) in marks.iter().filter(|(_, m)| matches!(m, Mark::Layer(_))) {
+            if let Some(o) = objects.get(n) {
+                unbox(&pdf, o, &mut patch)?;
+            }
+        }
     }
     let pdf = patch.apply(&pdf, &xref)?;
     // The file still is what its standard says.
@@ -235,8 +266,9 @@ pub(crate) fn finish(pdf: Vec<u8>, doc: &Document, set: &PdfSettings, layers: bo
     Ok(pdf)
 }
 
-/// The optional content groups of `doc`'s top-level layers, the uses of their forms marked as
-/// their content, and the catalog's `/OCProperties`.
+/// The optional content groups of `doc`'s layers and sublayers ([`pdf_layers`]), the uses of their
+/// forms marked as their content, and the catalog's `/OCProperties`, listing sublayers under their
+/// layers.
 fn write_layers(
     pdf: &[u8],
     xref: &Xref,
@@ -247,11 +279,16 @@ fn write_layers(
     set: &PdfSettings,
 ) -> Result<(), PdfError> {
     // One group per layer, in paint order (bottom first).
+    let layers = pdf_layers(doc);
     let mut groups: HashMap<usize, u32> = HashMap::new();
     let (mut all, mut off, mut locked) = (vec![], vec![], vec![]);
-    for (i, l) in doc.layers.iter().enumerate() {
-        let NodeKind::Layer { template: false, printable, .. } = l.kind else { continue };
-        let name = l.name.clone().unwrap_or_else(|| format!("Layer {}", i + 1));
+    // Each layer's sublayers, and the top-level layers, in paint order.
+    let mut children: HashMap<Option<usize>, Vec<usize>> = HashMap::new();
+    for (i, PdfLayer { node: l, parent }) in layers.iter().enumerate() {
+        let siblings = children.entry(*parent).or_default();
+        siblings.push(i);
+        let name = l.name.clone().unwrap_or_else(|| format!("Layer {}", siblings.len()));
+        let printable = matches!(l.kind, NodeKind::Layer { printable: true, .. });
         let on = |b: bool| if b { "ON" } else { "OFF" };
         let g = patch.add_object(
             format!("<</Type/OCG/Name{}/Usage<</View<</ViewState/{}>>/Print<</PrintState/{}>>>>>>", text_string(&name), on(l.visible), on(printable))
@@ -295,9 +332,7 @@ fn write_layers(
         add_resources(patch, res, "Properties", &entries)?;
     }
     let refs = |v: &[u32]| v.iter().map(|g| format!("{g} 0 R")).collect::<Vec<_>>().join(" ");
-    // Layers panels list the top layer first.
-    let order: Vec<u32> = all.iter().rev().copied().collect();
-    let mut config = format!("/Name(Layers)/Order[{}]", refs(&order));
+    let mut config = format!("/Name(Layers)/Order[{}]", order(&children, &groups, None));
     if !off.is_empty() {
         config.push_str(&format!("/OFF[{}]", refs(&off)));
     }
@@ -313,3 +348,35 @@ fn write_layers(
     patch.replace(start + 2, start + 2, format!("/OCProperties<</OCGs[{}]/D<<{config}>>>>", refs(&all)).into_bytes());
     Ok(())
 }
+
+/// A form's box as large as a page can be: the box of a layer's form is only the bounds of its
+/// art, and a reader that makes a clipping group of a form's box (as importers do) would gather a
+/// layer's art and its sublayers' in one group, which no layer can hold. A box round the whole
+/// page clips nothing.
+const UNBOXED: &[u8] = b"[-32767 -32767 32767 32767]";
+
+/// Give the layer's form `o` the [`UNBOXED`] box.
+fn unbox(pdf: &[u8], o: &Object<'_>, patch: &mut Patch) -> Result<(), PdfError> {
+    let Obj::Dict { start, end, .. } = o.dict else { return Err(bad("a layer's form has no dictionary")) };
+    let dict = pdf.get(start..end).ok_or_else(|| bad("a layer's form can't be read"))?;
+    // The writer writes the box as an array of numbers.
+    let at = dict.windows(5).position(|w| w == b"/BBox").ok_or_else(|| bad("a layer's form has no box"))? + 5;
+    let open = at + dict.get(at..).and_then(|d| d.iter().position(|&c| c == b'[')).ok_or_else(|| bad("a layer's form box isn't an array"))?;
+    let close = open + dict.get(open..).and_then(|d| d.iter().position(|&c| c == b']')).ok_or_else(|| bad("a layer's form box isn't an array"))? + 1;
+    patch.replace(start + open, start + close, UNBOXED.to_vec());
+    Ok(())
+}
+
+/// The `/Order` entries of `parent`'s sublayers (the top-level layers for none), the top one first
+/// as Layers panels list them, each followed by an array of its own sublayers when it has some.
+fn order(children: &HashMap<Option<usize>, Vec<usize>>, groups: &HashMap<usize, u32>, parent: Option<usize>) -> String {
+    let mut out = vec![];
+    for &i in children.get(&parent).into_iter().flatten().rev() {
+        let Some(g) = groups.get(&i) else { continue };
+        out.push(format!("{g} 0 R"));
+        if children.contains_key(&Some(i)) {
+            out.push(format!("[{}]", order(children, groups, Some(i))));
+        }
+    }
+    out.join(" ")
+}
diff --git a/crates/pdf/src/import.rs b/crates/pdf/src/import.rs
index f9f6db07..0bace225 100644
--- a/crates/pdf/src/import.rs
+++ b/crates/pdf/src/import.rs
@@ -537,14 +537,23 @@ struct Frame {
     children: Vec<Arc<Node>>,
     /// The first optional content group entered inside (where the frame's art goes).
     group: Option<usize>,
+    /// The group each child was drawn in, where the frame's art goes when the frame dissolves
+    /// into its parent (a layer's form drawing its sublayers' forms).
+    child_groups: Vec<Option<usize>>,
 }
 
 impl Frame {
     fn new(kind: FrameKind) -> Self {
-        Self { kind, children: vec![], group: None }
+        Self { kind, children: vec![], group: None, child_groups: vec![] }
     }
 }
 
+/// A dissolving frame's `children`, each with the group it was drawn in (`groups`, else the
+/// frame's `group`).
+fn grouped(children: Vec<Arc<Node>>, groups: Vec<Option<usize>>, group: Option<usize>) -> impl Iterator<Item = (Arc<Node>, Option<usize>)> {
+    children.into_iter().zip(groups.into_iter().map(move |g| g.or(group)).chain(std::iter::repeat(group)))
+}
+
 /// Glyphs drawn consecutively with the same paint, merged into one path.
 struct GlyphRun {
     path: BezPath,
@@ -846,8 +855,11 @@ impl<'p> Builder<'p> {
         // A frame's art goes where its first art was drawn (a clip can end in a later group).
         if root {
             self.root_groups.push(group.or(current));
-        } else if f.group.is_none() {
-            f.group = group.or(current);
+        } else {
+            f.child_groups.push(group.or(current));
+            if f.group.is_none() {
+                f.group = group.or(current);
+            }
         }
     }
 
@@ -925,7 +937,7 @@ impl<'p> Builder<'p> {
         let node = match f.kind {
             FrameKind::Root => None,
             FrameKind::Skip => {
-                f.children.into_iter().for_each(|c| self.emit(c, group));
+                grouped(f.children, f.child_groups, group).for_each(|(c, g)| self.emit(c, g));
                 None
             }
             FrameKind::Clip(clip) => {
@@ -934,7 +946,7 @@ impl<'p> Builder<'p> {
                     None
                 } else if noop.is_some_and(|r| bounds(&f.children).is_some_and(|b| contains(r, b))) {
                     // A rectangle around all of its art (a form's box) clips nothing.
-                    f.children.into_iter().for_each(|c| self.emit(c, group));
+                    grouped(f.children, f.child_groups, group).for_each(|(c, g)| self.emit(c, g));
                     None
                 } else {
                     let mut ch = vec![Arc::new(*clip)];
@@ -957,7 +969,7 @@ impl<'p> Builder<'p> {
                 if children.is_empty() {
                     None
                 } else if plain {
-                    children.into_iter().for_each(|c| self.emit(c, group));
+                    grouped(children, f.child_groups, group).for_each(|(c, g)| self.emit(c, g));
                     None
                 } else if let [only] = children.as_slice()
                     && !only.is_container()
diff --git a/crates/pdf/src/lib.rs b/crates/pdf/src/lib.rs
index 2cbc4176..26174e8f 100644
--- a/crates/pdf/src/lib.rs
+++ b/crates/pdf/src/lib.rs
@@ -10,7 +10,7 @@
 //!   text in embedded subset fonts (Advanced). Colours are converted, tagged with ICC profiles and
 //!   given an output intent as the Output settings say. Hidden objects,
 //!   guides and template layers are skipped, and so are non-printing layers unless asked for.
-//!   Top-level layers can be PDF layers (optional content groups with their visibility, print
+//!   Layers and sublayers can be PDF layers (optional content groups with their visibility, print
 //!   state and lock), and overprinting fills and strokes overprint (Advanced).
 //!   Each page is its artboard (the trim box) grown by the bleed (the bleed box) and by the
 //!   printer's marks around it (the media box), drawn in Registration. [`PdfSettings`] is the Save PDF
diff --git a/crates/pdf/src/settings.rs b/crates/pdf/src/settings.rs
index b01a3036..d81b7d5d 100644
--- a/crates/pdf/src/settings.rs
+++ b/crates/pdf/src/settings.rs
@@ -226,7 +226,7 @@ pub struct PdfSettings {
     pub fast_web_view: bool,
     /// The app opens the written file (frontends only; the writer ignores it).
     pub view_after_saving: bool,
-    /// Write top-level layers as PDF layers (optional content).
+    /// Write layers and sublayers as PDF layers (optional content).
     pub create_layers: bool,
     /// Keep the layers whose Print option is off (they are left out otherwise, unless
     /// `create_layers` is on).
@@ -449,7 +449,7 @@ impl PdfSettings {
         within("advanced.fontSubsetPercent", self.advanced.font_subset_percent, 0.0, 100.0, "%")
     }
 
-    /// Top-level layers are written as PDF layers: asked for, at a version that has them.
+    /// Layers and sublayers are written as PDF layers: asked for, at a version that has them.
     pub fn writes_layers(&self) -> bool {
         self.create_layers && self.compatibility.has_layers()
     }
diff --git a/crates/pdf/src/tests_layers.rs b/crates/pdf/src/tests_layers.rs
index ba4d39f0..197090ab 100644
--- a/crates/pdf/src/tests_layers.rs
+++ b/crates/pdf/src/tests_layers.rs
@@ -131,6 +131,57 @@ fn pdf_layers_import_back_as_layers() {
     }
 }
 
+/// The rows of `nodes` in paint order, depth first: `depth name visible` for layers, `depth fill`
+/// for art.
+fn tree(nodes: &[std::sync::Arc<Node>], depth: usize, out: &mut Vec<String>) {
+    for n in nodes {
+        match &n.kind {
+            NodeKind::Layer { children, .. } => {
+                out.push(format!("{depth} {} {}", n.name.clone().unwrap_or_default(), n.visible));
+                tree(children, depth + 1, out);
+            }
+            _ => out.push(format!("{depth} {:?}", n.appearance.fill().and_then(|f| f.paint.color()))),
+        }
+    }
+}
+
+/// Sublayers are PDF layers listed under their layer's, hidden ones off with their art, and they
+/// import back as sublayers (#372: other apps read a `.ai` file's PDF part).
+#[test]
+fn sublayers_are_nested_pdf_layers_and_import_back() {
+    let mut d = Document::new(200.0, 100.0);
+    d.layers.clear();
+    let layer = |d: &mut Document, name: &str, visible: bool, children: Vec<Node>| {
+        let mut l = Node::layer(d.alloc_id(), name, LayerColor::Preset(0));
+        l.visible = visible;
+        if let NodeKind::Layer { children: c, .. } = &mut l.kind {
+            c.extend(children.into_iter().map(std::sync::Arc::new));
+        }
+        l
+    };
+    let deep = vec![rect(&mut d, 90.0, GREEN)];
+    let deep = layer(&mut d, "Deep", true, deep);
+    let sub = vec![rect(&mut d, 50.0, BLUE), deep];
+    let sub = layer(&mut d, "Sub", false, sub);
+    let main = vec![rect(&mut d, 10.0, RED), sub];
+    let main = layer(&mut d, "Main", true, main);
+    d.layers.push(main.into());
+    let r = export(&d, json!({"createLayers": true, "compression": {"compressText": false}}));
+    oc_properties(&r.bytes, None, |props, xref| {
+        let props = props.expect("/OCProperties");
+        assert_eq!(names(xref, props.get(b"OCGs")), ["Main", "Sub", "Deep"]);
+        assert_eq!(names(xref, props.get::<Dict<'_>>(b"D").unwrap().get(b"OFF")), ["Sub"]);
+    });
+    let text = String::from_utf8_lossy(&r.bytes);
+    let order = text.split("/Order").nth(1).and_then(|o| o.split("]/").next()).unwrap().to_string();
+    assert_eq!(order.matches('[').count(), 3, "each layer's sublayers in an array after it: {order}");
+    let mut got = vec![];
+    tree(&import(&r.bytes).unwrap().layers, 0, &mut got);
+    // Paint order, as it was.
+    let fill = |depth, c: Color| format!("{depth} {:?}", Some(c));
+    assert_eq!(got, ["0 Main true".to_string(), fill(1, RED), "1 Sub false".into(), fill(2, BLUE), "2 Deep true".into(), fill(3, GREEN)]);
+}
+
 #[test]
 fn identical_layers_stay_apart() {
     let mut d = Document::new(200.0, 100.0);
diff --git a/crates/ui-egui/src/dialogs/save_pdf.rs b/crates/ui-egui/src/dialogs/save_pdf.rs
index 3c7bc79c..0cb7b627 100644
--- a/crates/ui-egui/src/dialogs/save_pdf.rs
+++ b/crates/ui-egui/src/dialogs/save_pdf.rs
@@ -455,7 +455,7 @@ fn general(ui: &mut egui::Ui, d: &mut Dialog, editor: bool) {
     flag(ui, d, "viewAfterSaving", tl!("View PDF after saving"), true);
     // PDF layers need PDF 1.5, and PDF/X-1a and PDF/X-3 have none.
     let layers = standard.allows_layers() && choice::<Compatibility>(d, "compatibility").unwrap_or_default().has_layers();
-    flag(ui, d, "createLayers", tl!("Create PDF layers from top-level layers"), layers);
+    flag(ui, d, "createLayers", tl!("Create PDF layers from layers and sublayers"), layers);
     flag(ui, d, "includeNonPrinting", tl!("Include non-printing layers"), true);
     if editor {
         heading(ui, tl!("Description"));
diff --git a/crates/ui-egui/src/i18n/es.tsv b/crates/ui-egui/src/i18n/es.tsv
index e4ceed41..e0bf847b 100644
--- a/crates/ui-egui/src/i18n/es.tsv
+++ b/crates/ui-egui/src/i18n/es.tsv
@@ -508,7 +508,7 @@
 	Create Object Mosaic…	Crear mosaico de objetos…
 	Create Outlines	Crear contornos
 	Create Path	Crear trazado
-	Create PDF layers from top-level layers	Crear capas PDF a partir de las capas de nivel superior
+	Create PDF layers from layers and sublayers	Crear capas PDF a partir de las capas y subcapas
 	Create PDF-Compatible File	Crear archivo compatible con PDF
 	Create Report	Crear informe
 	Create Slice	Crear sector
diff --git a/crates/ui-egui/src/i18n/it.tsv b/crates/ui-egui/src/i18n/it.tsv
index decd91fd..0d0abf3d 100644
--- a/crates/ui-egui/src/i18n/it.tsv
+++ b/crates/ui-egui/src/i18n/it.tsv
@@ -508,7 +508,7 @@
 	Create Object Mosaic…	Crea mosaico di oggetti…
 	Create Outlines	Crea contorni
 	Create Path	Crea tracciato
-	Create PDF layers from top-level layers	Crea livelli PDF dai livelli principali
+	Create PDF layers from layers and sublayers	Crea livelli PDF dai livelli e sottolivelli
 	Create PDF-Compatible File	Crea file compatibile PDF
 	Create Report	Crea rapporto
 	Create Slice	Crea sezione
diff --git a/crates/ui-egui/src/i18n/ja.tsv b/crates/ui-egui/src/i18n/ja.tsv
index b479ea62..0576ef31 100644
--- a/crates/ui-egui/src/i18n/ja.tsv
+++ b/crates/ui-egui/src/i18n/ja.tsv
@@ -983,7 +983,7 @@
 	Create New Sublayer	新規サブレイヤーを作成
 	Create New Swatch…	新規スウォッチを作成…
 	Create New {kind} Style	新しい{kind}スタイルを作成
-	Create PDF layers from top-level layers	最上位レイヤーから PDF レイヤーを作成
+	Create PDF layers from layers and sublayers	レイヤーとサブレイヤーから PDF レイヤーを作成
 	Create PDF-Compatible File	PDF 互換ファイルを作成
 	Create Path	パスを作成
 	Create Slice	スライスを作成
diff --git a/crates/ui-egui/src/i18n/pt-br.tsv b/crates/ui-egui/src/i18n/pt-br.tsv
index 9500ba89..5d74b821 100644
--- a/crates/ui-egui/src/i18n/pt-br.tsv
+++ b/crates/ui-egui/src/i18n/pt-br.tsv
@@ -497,7 +497,7 @@
 	Create New {kind} Style	Criar Novo Estilo de {kind}
 	Create Object Mosaic…	Criar Mosaico de Objetos…
 	Create Outlines	Criar Contornos
-	Create PDF layers from top-level layers	Criar camadas de PDF a partir das camadas de nível superior
+	Create PDF layers from layers and sublayers	Criar camadas de PDF a partir das camadas e subcamadas
 	Create PDF-Compatible File	Criar Arquivo Compatível com PDF
 	Create Path	Criar Caminho
 	Create Slice	Criar Fatia
diff --git a/crates/ui-egui/src/i18n/ru.tsv b/crates/ui-egui/src/i18n/ru.tsv
index 53cafffa..a40acd24 100644
--- a/crates/ui-egui/src/i18n/ru.tsv
+++ b/crates/ui-egui/src/i18n/ru.tsv
@@ -506,7 +506,7 @@
 	Create Object Mosaic…	Создать мозаику объектов…
 	Create Outlines	Создать контуры
 	Create Path	Создать контур
-	Create PDF layers from top-level layers	Создавать слои PDF из слоёв верхнего уровня
+	Create PDF layers from layers and sublayers	Создавать слои PDF из слоёв и подслоёв
 	Create PDF-Compatible File	Создать файл, совместимый с PDF
 	Create Report	Создать отчёт
 	Create Slice	Создать фрагмент
diff --git a/crates/ui-egui/src/i18n/zh-hans.tsv b/crates/ui-egui/src/i18n/zh-hans.tsv
index ddc8134f..1c6f1734 100644
--- a/crates/ui-egui/src/i18n/zh-hans.tsv
+++ b/crates/ui-egui/src/i18n/zh-hans.tsv
@@ -508,7 +508,7 @@
 	Create Object Mosaic…	创建对象马赛克…
 	Create Outlines	创建轮廓
 	Create Path	创建路径
-	Create PDF layers from top-level layers	从顶层图层创建 PDF 图层
+	Create PDF layers from layers and sublayers	从图层和子图层创建 PDF 图层
 	Create PDF-Compatible File	创建与 PDF 兼容的文件
 	Create Report	创建报告
 	Create Slice	创建切片
diff --git a/crates/ui-egui/src/i18n/zh-hant.tsv b/crates/ui-egui/src/i18n/zh-hant.tsv
index a9d704ba..55723ec8 100644
--- a/crates/ui-egui/src/i18n/zh-hant.tsv
+++ b/crates/ui-egui/src/i18n/zh-hant.tsv
@@ -523,7 +523,7 @@
 	Create Object Mosaic…	建立物件馬賽克…
 	Create Outlines	建立外框
 	Create Path	建立路徑
-	Create PDF layers from top-level layers	從最上層圖層建立 PDF 圖層
+	Create PDF layers from layers and sublayers	從圖層和子圖層建立 PDF 圖層
 	Create PDF-Compatible File	建立與 PDF 相容的檔案
 	Create Report	建立報告
 	Create Slice	建立切片
diff --git a/docs/mcp.md b/docs/mcp.md
index b3ab77bf..16030f18 100644
--- a/docs/mcp.md
+++ b/docs/mcp.md
@@ -355,9 +355,11 @@ A `security` password encrypts the file (RC4 40-bit at PDF 1.3, RC4 128-bit at 1
 Pattern fills and strokes are written as their tiles clipped to the area they paint (a stroke's outline, with its
 dashes, caps, profile, arrowheads and alignment), and freeform gradients as an image of their colour field at the
 document's raster effects resolution, clipped the same way.
-`createLayers` writes each top-level layer (template layers are left out) as a PDF layer, an optional content group
-named as the layer: hidden layers are off, non-printing ones have `/PrintState /OFF` and locked ones are locked. It needs
-PDF 1.5 or later (at 1.4 it warns), and the file reopens with those layers.
+`createLayers` writes each layer and sublayer (template layers are left out) as a PDF layer, an optional content group
+named as the layer and listed under its parent layer's: hidden layers are off (their art is written, for the reader to
+show), non-printing ones have `/PrintState /OFF` and locked ones are locked. It needs PDF 1.5 or later (at 1.4 it
+warns), and the file reopens with those layers and sublayers. A `.ai` file writes them unless `createLayers` is false,
+so apps that read its PDF part find the layers, hidden ones included; hidden objects aren't in the PDF part.
 Images follow the `compression` settings of their kind (`color`, `gray`, or `mono` for black-and-white images): above
 `abovePpi` as placed they are resampled (`downsample`: `average`, `subsample` or `bicubic`) to `ppi`, and compressed
 with `zip`, `jpeg` (at `quality`; images with transparency stay lossless) or `auto` (JPEGs stay JPEG, the others