diff --git a/crates/engine/src/cmd/fileio/pdf.rs b/crates/engine/src/cmd/fileio/pdf.rs
index 641aa0845..14b692e73 100644
--- a/crates/engine/src/cmd/fileio/pdf.rs
+++ b/crates/engine/src/cmd/fileio/pdf.rs
@@ -282,7 +282,7 @@ fn overflow_warning(cmd: &str, doc: &Document, p: &Value) -> Result<Option<Strin
 
 /// [`encode`] the pages of `doc`, carrying `native()` as the editing data (a `.ai` file: the
 /// native document with its save options, whose pages may be left blank), and `private()`, the
-/// editing copy of the art for other apps with what it couldn't hold, on the first page.
+/// editing copy of the art for other apps with what it couldn't hold, on every page.
 pub(super) fn encode_carrying(
     cmd: &str,
     doc: &Document,
diff --git a/crates/eps/src/ai_editing.rs b/crates/eps/src/ai_editing.rs
index 272e92755..552a99fe0 100644
--- a/crates/eps/src/ai_editing.rs
+++ b/crates/eps/src/ai_editing.rs
@@ -1,4 +1,4 @@
-//! The editing copy of the art that a PDF-compatible `.ai` file carries in its first page's
+//! The editing copy of the art that a PDF-compatible `.ai` file carries in its pages'
 //! `PieceInfo` ([`vectorcraft_pdf::PrivateData`]): the document's layers, sublayers, groups, paths,
 //! colors, swatches and artboards in the form [`crate::import`]'s `.ai` reader reads, so that apps
 //! that open `.ai` files from that copy get them as editable objects.
@@ -8,16 +8,18 @@
 //! groups and compound paths (§5.3.5), guides (§6) and layers (§9), with the newer forms the reader
 //! reads from files users sent:
 //!
-//! - Header comments: `%%For` (the document's author), `%%Canvassize`, `%%BoundingBox`,
+//! - Header comments: `%%Creator` (naming the format's app, see [`CREATOR_TEXT`]), `%%For` (the
+//!   document's author), `%%Canvassize`, `%%BoundingBox`,
 //!   `%%HiResBoundingBox`, `%AI5_FileFormat 14.0`, `%AI7_ImageSettings`, the first artboard as
-//!   `%AI3_Cropmarks` and `%AI5_ArtSize`, `%AI5_RulerUnits`, `%AI9_ColorModel` (1 RGB, 2 CMYK),
+//!   `%AI3_Cropmarks` and `%AI3_TileBox`, the canvas's center as `%AI3_TemplateBox`,
+//!   `%AI5_ArtSize 14400 14400`, `%AI5_RulerUnits`, `%AI9_ColorModel` (1 RGB, 2 CMYK),
 //!   `%AI5_ArtFlags`, `%AI5_TargetResolution`, `%AI5_NumLayers`, `%AI5_OpenViewLayers` (a digit for
 //!   each layer, 7 shown and 6 hidden), `%AI7_GridSettings` (§2.1.1), and the version comment
 //!   `%%AI8_CreatorVersion` ([`CREATOR_VERSION`]).
 //! - Setup: `0 Bn` (no gradient definitions, §3), the color swatches (`%AI5_BeginPalette`,
 //!   `0 0 Pb`, the Registration swatch, each swatch's color operator and `(name) Pc`, a color group as `0 (name) count Pg`
 //!   before its swatches, `PB`), then the artboards as the `ArtboardArray` of the `/Document`
-//!   dictionary, on `%_` lines.
+//!   dictionary and the canvas size as its `AIDocumentCanvasSize`, on `%_` lines.
 //! - Layers: `%AI5_BeginLayer`, `visible preview unlocked printing dimmed 0 1 colorIndex r g b 0
 //!   dimPercent 0 Lb` (14 operands; a color that isn't one of the preset layer colors has the
 //!   index -1), `(name) Ln`, the layer's name as an XML id in an `/ArtDictionary`, its art and
@@ -30,8 +32,10 @@
 //!   an `/ArtDictionary` whose `AI10_ArtUID` is the name as an XML id. Guides are `(N) *`, the
 //!   path, `(N) *` (`(n) *` when closed).
 //!
-//! Lines end in CR LF. Strings are written in UTF-8. Art space has y up, its origin at the first artboard's bottom-left
-//! corner. What the form above can't hold is written as plain filled and stroked paths, each such
+//! Lines end in CR LF. Strings are written in UTF-8. Art space is ruler space: y up, its origin at
+//! the first artboard's top-left corner. On the canvas ([`CANVAS_SIZE`] points square, y down) the
+//! artboards together are centered; each artboard's `RulerOrigin` is its top-left corner there, and
+//! `%AI3_TemplateBox` holds the canvas's center in art space. What the form above can't hold is written as plain filled and stroked paths, each such
 //! loss a warning: type as its outlines, gradients as their average color, pattern fills as their
 //! tiles cut to the shape, clipping groups and clipping layers as their art cut to the clipping
 //! path (the clipping path's fill cut too, its stroke not), images as their outlines filled with
@@ -67,6 +71,8 @@ const ROUNDTRIP_STREAM_TYPE: u32 = 2;
 const ZSTD_MARKER: &[u8] = b"%AI24_ZStandard_Data";
 /// `%%Canvassize`: the side of the canvas in points, as the files users sent have it.
 const CANVAS_SIZE: u32 = 16383;
+/// `%AI5_ArtSize`, as the files users sent have it.
+const ART_SIZE: u32 = 14400;
 /// `%AI5_ArtFlags` (§2.1.1, Table 4), as the files users sent have them: page setup, print tiles,
 /// placed images, preview patterns, split long paths, tile full pages, printer's default
 /// screens, auto default screens, compatible gradient printing.
@@ -76,6 +82,13 @@ const TARGET_RESOLUTION: u32 = 800;
 /// The gridlines' gray: VectorCraft's default grid color (200 of 255).
 const GRID_GRAY: f64 = 200.0 / 255.0;
 
+/// `%%Creator`. Apps that read the editing data take the file's version from this line while they
+/// read the header, and only a creator that names the format's app gets the version that measures
+/// `%AI3_TemplateBox` on a canvas of [`CANVAS_SIZE`] points; any other creator places the art
+/// 3,871.5 points off its artboard. The text holds no version number (a number in it would be
+/// read as the format's version).
+const CREATOR_TEXT: &str = "VectorCraft, editing data for Illustrator"; // brand-ok: the creator the format's version is read from
+
 /// The first line of a PostScript file (the DSC version comment).
 const PS_HEADER: &str = "%!PS-Adobe-3.0"; // brand-ok: the PostScript header comment
 
@@ -107,13 +120,14 @@ pub fn export_ai_editing(doc: &Document, o: &AiEditingOptions) -> Result<AiEditi
     // Live geometry effects as their result, as the PDF part draws them.
     let baked = baked(doc);
     let doc = baked.as_ref().unwrap_or(doc);
-    // The document is y down; art space y up from the first artboard's bottom-left corner.
-    let to_art = Affine::new([1.0, 0.0, 0.0, -1.0, -board.x0, board.y1]);
+    // The document is y down; art space is ruler space: y up, its origin the first artboard's
+    // top-left corner.
+    let to_art = Affine::new([1.0, 0.0, 0.0, -1.0, -board.x0, board.y0]);
     let mut w = Writer::new(doc, to_art);
     for layer in &doc.layers {
         w.layer(layer);
     }
-    let (width, height) = (board.width(), board.height());
+    let first = to_art.transform_rect_bbox(board);
     let art = doc
         .layers
         .iter()
@@ -122,13 +136,14 @@ pub fn export_ai_editing(doc: &Document, o: &AiEditingOptions) -> Result<AiEditi
         .map(|b| to_art.transform_rect_bbox(b))
         .filter(|b| b.is_finite())
         .reduce(|a, b| a.union(b))
-        .unwrap_or(Rect::new(0.0, 0.0, width, height));
-    let header = header(doc, o, &w, art, (width, height));
+        .unwrap_or(first);
+    let origin = ruler_origin(doc, to_art);
+    let header = header(doc, o, &w, art, first, origin);
     let mut s = header.clone();
     // No gradient definitions: gradients are written as their average color.
     s.push_str("%%BeginProlog\n%%EndProlog\n%%BeginSetup\n0 Bn\n");
     w.palette(&mut s);
-    artboards(&mut s, doc, to_art);
+    artboards(&mut s, doc, to_art, origin);
     s.push_str("%%EndSetup\n");
     s.push_str(&w.body);
     s.push_str("%%PageTrailer\ngsave annotatepage grestore showpage\n%%Trailer\n%%EOF\n");
@@ -164,7 +179,7 @@ fn baked(doc: &Document) -> Option<Document> {
     Some(out)
 }
 
-/// The editing data of `doc` as a `.ai` file's first page carries it: the program compressed with
+/// The editing data of `doc` as a `.ai` file's pages carry it: the program compressed with
 /// Zstandard after `%AI24_ZStandard_Data`, its header as the `AIMetaData`, and the version numbers
 /// that go with that form; and what it couldn't hold.
 pub fn private_data(doc: &Document, o: &AiEditingOptions) -> Result<(PrivateData, Vec<String>), String> {
@@ -182,13 +197,28 @@ pub fn private_data(doc: &Document, o: &AiEditingOptions) -> Result<(PrivateData
     Ok((p, out.warnings))
 }
 
-/// The header comments, through `%%EndComments`. `art`: the visible art's bounds, `size` the first
-/// artboard's, in art space.
-fn header(doc: &Document, o: &AiEditingOptions, w: &Writer, art: Rect, (width, height): (f64, f64)) -> String {
+/// Where art space's origin lies on the canvas (y down, [`CANVAS_SIZE`] points square): the
+/// artboards together centered on the canvas's center, on whole points, as the files users sent
+/// place them.
+fn ruler_origin(doc: &Document, to_art: Affine) -> (f64, f64) {
+    let all = doc.artboards.iter().map(|ab| to_art.transform_rect_bbox(ab.rect)).filter(|r| r.is_finite()).reduce(|a, b| a.union(b));
+    let c = all.map_or((0.0, 0.0), |r| (r.center().x, r.center().y));
+    let mid = canvas_center();
+    ((mid - c.0).floor(), (mid + c.1).floor())
+}
+
+/// The canvas's center, on its own axes and in both directions.
+fn canvas_center() -> f64 {
+    f64::from(CANVAS_SIZE) / 2.0
+}
+
+/// The header comments, through `%%EndComments`. `art`: the visible art's bounds, `first` the first
+/// artboard, in art space; `origin` art space's origin on the canvas ([`ruler_origin`]).
+fn header(doc: &Document, o: &AiEditingOptions, w: &Writer, art: Rect, first: Rect, origin: (f64, f64)) -> String {
     let mut s = String::new();
     s.push_str(PS_HEADER);
     s.push('\n');
-    let _ = writeln!(s, "%%Creator: VectorCraft {}", env!("CARGO_PKG_VERSION"));
+    let _ = writeln!(s, "%%Creator: {CREATOR_TEXT}");
     let _ = writeln!(s, "%%AI8_CreatorVersion: {CREATOR_VERSION}");
     // The user and the organization (§2.1.1).
     let _ = writeln!(s, "%%For: {} ()", ps::bytes(doc.metadata.author.as_bytes()));
@@ -216,13 +246,17 @@ fn header(doc: &Document, o: &AiEditingOptions, w: &Writer, art: Rect, (width, h
         ps::push_nums(&mut s, &cmyk.map(f64::from));
         let _ = writeln!(s, "{}", ps::bytes(name.as_bytes()));
     }
-    let (w2, h2) = (ps::num(width), ps::num(height));
-    let _ = writeln!(s, "%AI3_Cropmarks: 0 0 {w2} {h2}");
-    let (cx, cy) = (ps::num(width / 2.0), ps::num(height / 2.0));
+    // The first artboard, left, bottom, right, top.
+    let mut board = String::new();
+    ps::push_nums(&mut board, &[first.x0, first.y0, first.x1, first.y1]);
+    board.pop();
+    let _ = writeln!(s, "%AI3_Cropmarks: {board}");
+    // The canvas's center in art space.
+    let (cx, cy) = (ps::num(canvas_center() - origin.0), ps::num(origin.1 - canvas_center()));
     let _ = writeln!(s, "%AI3_TemplateBox: {cx} {cy} {cx} {cy}");
-    let _ = writeln!(s, "%AI3_TileBox: 0 0 {w2} {h2}");
+    let _ = writeln!(s, "%AI3_TileBox: {board}");
     s.push_str("%AI3_DocumentPreview: None\n");
-    let _ = writeln!(s, "%AI5_ArtSize: {w2} {h2}");
+    let _ = writeln!(s, "%AI5_ArtSize: {ART_SIZE} {ART_SIZE}");
     let _ = writeln!(s, "%AI5_RulerUnits: {}", ruler_units(doc.units));
     s.push_str("%AI24_LargeCanvasScale: 1\n");
     let model = if doc.color_mode == vectorcraft_doc::ColorMode::Cmyk { 2 } else { 1 };
@@ -256,19 +290,30 @@ fn ruler_units(u: Unit) -> u8 {
 }
 
 /// The artboards as the `ArtboardArray` of the `/Document` dictionary: each one's top-left and
-/// bottom-right corners in art space (`PositionPoint1`, `PositionPoint2`) and its name.
-fn artboards(s: &mut String, doc: &Document, to_art: Affine) {
+/// bottom-right corners in art space (`PositionPoint1`, `PositionPoint2`), its top-left corner on
+/// the canvas (`RulerOrigin`, `origin` being art space's origin there), its pixel aspect ratio
+/// (`PAR`), `DisplayMark` 0 (as in the files users sent), whether it is the selected one (the
+/// first) and its name; then the canvas's size. Apps that read the editing data drop a record that
+/// lacks any of the first five.
+fn artboards(s: &mut String, doc: &Document, to_art: Affine, origin: (f64, f64)) {
     s.push_str("%AI9_BeginDocumentData\n%_/Document :\n%_/Dictionary :\n%_/Array :\n");
-    for ab in &doc.artboards {
+    for (i, ab) in doc.artboards.iter().enumerate() {
         let r = to_art.transform_rect_bbox(ab.rect);
         s.push_str("%_/Dictionary :\n%_");
         ps::push_nums(s, &[r.x0, r.y1]);
         s.push_str("/RealPointRelToROrigin\n%_ (PositionPoint1) ,\n%_");
         ps::push_nums(s, &[r.x1, r.y0]);
-        s.push_str("/RealPointRelToROrigin\n%_ (PositionPoint2) ,\n");
+        s.push_str("/RealPointRelToROrigin\n%_ (PositionPoint2) ,\n%_");
+        ps::push_nums(s, &[origin.0 + r.x0, origin.1 - r.y1]);
+        s.push_str("/RealPoint\n%_ (RulerOrigin) ,\n%_");
+        let par = ab.video_ruler_pixel_aspect_ratio;
+        ps::push_num(s, if par.is_finite() && par > 0.0 { par } else { 1.0 });
+        let _ = writeln!(s, " /Real (PAR) ,\n%_0 /Int (DisplayMark) ,\n%_{} /Bool (IsArtboardSelected) ,", u8::from(i == 0));
         let _ = writeln!(s, "%_{} /UnicodeString (Name) ,\n%_; ,", ps::bytes(ab.name.as_bytes()));
     }
-    s.push_str("%_; (ArtboardArray) ,\n%_; /NotRecorded ,\n%_;\n%AI9_EndDocumentData\n");
+    s.push_str("%_; (ArtboardArray) ,\n");
+    let _ = writeln!(s, "%_{CANVAS_SIZE} /Int (AIDocumentCanvasSize) ,");
+    s.push_str("%_; /NotRecorded ,\n%_;\n%AI9_EndDocumentData\n");
 }
 
 #[cfg(test)]
diff --git a/crates/eps/src/ai_editing/tests.rs b/crates/eps/src/ai_editing/tests.rs
index 402e34f4d..e7f9c9d39 100644
--- a/crates/eps/src/ai_editing/tests.rs
+++ b/crates/eps/src/ai_editing/tests.rs
@@ -290,8 +290,8 @@ fn the_data_is_zstandard_compressed_with_the_header_as_metadata() {
         "%%AI8_CreatorVersion: 30.7.0\n%%For: () ()\n%%Title: (Sample)\n",
         "%%Canvassize: 16383\n",
         "%AI5_FileFormat 14.0\n%AI3_ColorUsage: Color\n%AI7_ImageSettings: 0\n%%DocumentCustomColors: (Gold)\n%%+ (Sky)\n%%+ (Mint)\n",
-        "%AI3_Cropmarks: 0 0 200 100\n",
-        "%AI5_ArtSize: 200 100\n",
+        "%AI3_Cropmarks: 0 -100 200 0\n%AI3_TemplateBox: 225.5 -50.5 225.5 -50.5\n%AI3_TileBox: 0 -100 200 0\n",
+        "%AI5_ArtSize: 14400 14400\n",
         "%AI9_ColorModel: 1\n%AI5_ArtFlags: 0 0 0 1 0 0 1 0 0\n%AI5_TargetResolution: 800\n%AI5_NumLayers: 2\n",
         "%AI5_OpenViewLayers: 77\n%AI7_GridSettings: 72 8 72 8 1 0 0.7843 0.7843 0.7843 0.7843 0.7843 0.7843\n%%EndComments\n",
     ] {
@@ -300,6 +300,48 @@ fn the_data_is_zstandard_compressed_with_the_header_as_metadata() {
     assert_eq!((p.container_version, p.creator_version, p.roundtrip_version, p.roundtrip_stream_type), (12, 30, 24, 2));
 }
 
+/// Art space is ruler space: y up from the first artboard's top-left corner. The artboards
+/// together sit centered on the canvas: each one's top-left corner on the canvas (y down) is its
+/// `RulerOrigin`, and the template box holds the canvas's center in art space.
+#[test]
+fn art_lies_on_its_artboard_in_ruler_space() {
+    let mut doc = Document::new(200.0, 100.0);
+    let mut second = doc.artboards[0].clone();
+    (second.id, second.name, second.rect) = (2, "Back".into(), Rect::new(250.0, 0.0, 450.0, 100.0));
+    doc.artboards.push(second);
+    let rect = Node::path(
+        doc.alloc_id(),
+        shapes::rectangle(Rect::new(10.0, 20.0, 30.0, 40.0)),
+        Appearance::basic(solid(Color::gray(0.5)), Paint::None, 0.0),
+    );
+    let layer = doc.layers[0].id;
+    doc.insert(Some(layer), usize::MAX, rect).unwrap();
+    let text = program(&doc);
+    for line in [
+        "%%BoundingBox: 10 -40 30 -20\n",
+        "%AI3_Cropmarks: 0 -100 200 0\n",
+        "%AI3_TemplateBox: 225.5 -50.5 225.5 -50.5\n",
+        "\n10 -20 m\n",
+        "%_0 0 /RealPointRelToROrigin\n%_ (PositionPoint1) ,\n%_200 -100 /RealPointRelToROrigin\n%_ (PositionPoint2) ,\n%_7966 8141 /RealPoint\n%_ (RulerOrigin) ,\n%_1 /Real (PAR) ,\n%_0 /Int (DisplayMark) ,\n%_1 /Bool (IsArtboardSelected) ,\n",
+        "%_250 0 /RealPointRelToROrigin\n%_ (PositionPoint1) ,\n%_450 -100 /RealPointRelToROrigin\n%_ (PositionPoint2) ,\n%_8216 8141 /RealPoint\n%_ (RulerOrigin) ,\n%_1 /Real (PAR) ,\n%_0 /Int (DisplayMark) ,\n%_0 /Bool (IsArtboardSelected) ,\n",
+        "%_16383 /Int (AIDocumentCanvasSize) ,\n",
+    ] {
+        assert!(text.contains(line), "{line}\n{text}");
+    }
+    // The creator names the format's app, before the canvas size and the template box, and holds
+    // no version number another app could read as the format's version.
+    let creator = text.lines().find_map(|l| l.strip_prefix("%%Creator: ")).unwrap();
+    assert!(creator.contains("Illustrator"), "{creator}");
+    assert!(!creator.contains("88") && !creator.chars().any(|c| c.is_ascii_digit()), "{creator}");
+    assert!(text.find("%%Creator: ").unwrap() < text.find("%%Canvassize: 16383").unwrap());
+    assert!(text.find("%%Canvassize: 16383").unwrap() < text.find("%AI3_TemplateBox").unwrap());
+    // The reader puts the art back where it was, on its artboard.
+    let read = read_back(&doc);
+    assert_eq!(read.artboards.iter().map(|a| a.rect).collect::<Vec<_>>(), doc.artboards.iter().map(|a| a.rect).collect::<Vec<_>>());
+    let bounds = read.layers.iter().filter_map(|l| l.visual_bounds()).reduce(|a, b| a.union(b)).unwrap();
+    assert_eq!(bounds, Rect::new(10.0, 20.0, 30.0, 40.0));
+}
+
 #[test]
 fn a_pdf_carries_the_data_on_its_first_page() {
     let doc = sample();
diff --git a/crates/pdf/src/lib.rs b/crates/pdf/src/lib.rs
index 7ca44a4fd..c12459fbe 100644
--- a/crates/pdf/src/lib.rs
+++ b/crates/pdf/src/lib.rs
@@ -105,7 +105,7 @@ pub struct PdfOptions {
     pub modified: Option<i64>,
     /// The native document (`.vectorcraft` bytes) Preserve Editing embeds.
     pub native: Option<Vec<u8>>,
-    /// The editing copy of the art for the first page's `PieceInfo`, as a `.ai` file carries it.
+    /// The editing copy of the art for every page's `PieceInfo`, as a `.ai` file carries it.
     pub private_data: Option<PrivateData>,
     /// The pages drawn small, in page order: what Embed Page Thumbnails embeds (the writer
     /// doesn't draw; [`page_areas`] says what each page shows).
diff --git a/crates/pdf/src/piece_info.rs b/crates/pdf/src/piece_info.rs
index 157f36c5c..60cd80228 100644
--- a/crates/pdf/src/piece_info.rs
+++ b/crates/pdf/src/piece_info.rs
@@ -1,9 +1,11 @@
-//! An editor's private data on the first page: a page-piece dictionary (ISO 32000-1 §14.5,
+//! An editor's private data on every page: a page-piece dictionary (ISO 32000-1 §14.5,
 //! `PieceInfo`) holding the editing copy of the art that `.ai` files carry, laid out as in the
 //! `.ai` files users sent, the form [`crate::illustrator_data`] reads.
 //!
-//! - The page dictionary gets `/PieceInfo << /Illustrator n 0 R >>` and its own `/LastModified`
-//!   (which §14.5 requires with `PieceInfo`).
+//! - Every page dictionary gets `/PieceInfo << /Illustrator n 0 R >>`, the same object `n` on
+//!   each page, and its own `/LastModified` (which §14.5 requires with `PieceInfo`). A file with
+//!   several pages whose pages do not all refer to the one data dictionary opens in other apps as
+//!   a PDF, without the editing data.
 //! - Object `n` is the data dictionary: `<< /LastModified (D:…) /Private m 0 R >>`.
 //! - Object `m` holds `AIMetaData` (a stream of the data's header comments), `AIPrivateData1` …
 //!   `AIPrivateDataN` (the data in streams of [`PRIVATE_CHUNK`] bytes, the last one shorter),
@@ -35,12 +37,15 @@ pub struct PrivateData {
     pub roundtrip_stream_type: u32,
 }
 
-/// `pdf` with `p` in its first page's `PieceInfo`, dated `modified` (Unix seconds, UTC).
+/// `pdf` with `p` in every page's `PieceInfo`, dated `modified` (Unix seconds, UTC).
 pub(crate) fn add(pdf: Vec<u8>, p: &PrivateData, modified: i64) -> Result<Vec<u8>, PdfError> {
     let failed = |why: &str| PdfError::Write(format!("can't add the editing data for other apps: {why}"));
     let Parsed { xref, pages, .. } = linearize::parse(&pdf).map_err(failed)?;
-    let first = *pages.first().ok_or_else(|| failed("a page can't be read"))?;
-    let (dict, _) = xref.dict(&pdf, first).ok_or_else(|| failed("a page can't be read"))?;
+    if pages.is_empty() {
+        return Err(failed("a page can't be read"));
+    }
+    let dicts = pages.iter().map(|&n| xref.dict(&pdf, n).map(|(at, _)| at)).collect::<Option<Vec<usize>>>();
+    let dicts = dicts.ok_or_else(|| failed("a page can't be read"))?;
     let mut patch = Patch::new(&xref);
     let metadata = patch.add_object(stream(&p.metadata));
     let blocks: Vec<u32> = p.data.chunks(PRIVATE_CHUNK).map(|c| patch.add_object(stream(c))).collect();
@@ -60,7 +65,9 @@ pub(crate) fn add(pdf: Vec<u8>, p: &PrivateData, modified: i64) -> Result<Vec<u8
     let private = patch.add_object(private.into_bytes());
     let date = pdf_date(modified);
     let owner = patch.add_object(format!("<< /LastModified {date} /Private {private} 0 R >>").into_bytes());
-    patch.replace(dict, dict, format!("/PieceInfo << /{OWNER} {owner} 0 R >> /LastModified {date} ").into_bytes());
+    for dict in dicts {
+        patch.replace(dict, dict, format!("/PieceInfo << /{OWNER} {owner} 0 R >> /LastModified {date} ").into_bytes());
+    }
     patch.apply(&pdf, &xref)
 }
 
@@ -112,6 +119,30 @@ mod tests {
         assert!(text.contains(&format!("<< /Length {PRIVATE_CHUNK} >>")) && text.contains("<< /Length 10 >>"));
     }
 
+    #[test]
+    fn every_page_refers_to_the_one_data_dictionary() {
+        let mut doc = Document::new(200.0, 100.0);
+        let mut second = doc.artboards[0].clone();
+        (second.id, second.name, second.rect) = (2, "Back".into(), vectorcraft_geom::Rect::new(240.0, 0.0, 440.0, 100.0));
+        doc.artboards.push(second);
+        let opts = PdfOptions { private_data: Some(data(10)), ..PdfOptions::uncompressed() };
+        let pdf = export(&doc, &opts).unwrap();
+        let Parsed { xref, pages, .. } = linearize::parse(&pdf).unwrap();
+        assert_eq!(pages.len(), 2);
+        let owners: Vec<String> = pages
+            .iter()
+            .map(|&n| {
+                let (at, end) = xref.dict(&pdf, n).unwrap();
+                let page = String::from_utf8_lossy(&pdf[at..end]).into_owned();
+                assert!(page.contains("/LastModified (D:"), "{page}");
+                let i = page.find("/PieceInfo << /Illustrator ").expect("every page carries the data");
+                page[i..].split(">>").next().unwrap().to_string()
+            })
+            .collect();
+        assert_eq!(owners[0], owners[1]);
+        assert_eq!(String::from_utf8_lossy(&pdf).matches("/AIPrivateData1 ").count(), 1, "the data is written once");
+    }
+
     #[test]
     fn without_the_data_the_page_has_no_piece_info() {
         let pdf = export(&Document::new(200.0, 100.0), &PdfOptions::uncompressed()).unwrap();