A `.ai` file's PDF part is what apps that don't read VectorCraft's native
document open. It had no PDF layers: hidden layers and sublayers were left
out of it and everything else was flat page content.
- `.ai` files (Save As, exports, the CLI) write PDF layers unless
`createLayers` is false (a PDF standard still decides for itself).
- createLayers writes sublayers too, as optional content groups listed
under their layer's in `/Order`, hidden ones off with their art.
- A layer's form gets a box round the whole page instead of its art's
bounds, which readers made a clipping group of, gathering a layer's art
and its sublayers' in one group.
- PDF import: art inside a group, clip or form that dissolves into its
parent keeps the layer it was drawn in, so sublayers nested in their
layer's content import as sublayers.
- Save PDF: "Create PDF layers from layers and sublayers" (ja, es, it,
pt-br, ru, zh-hans, zh-hant).
Hidden objects (not layers) still aren't in the PDF part.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Advanced > Overprint: Preserve (the default; document.exportPdf
advanced.overprint) writes each overprinting fill and stroke (an object's
own, a character's, a type object's) with a graphics state of /OP true
/op true /OPM 1 (/OPM 0 in PDF/A); Discard writes none. White ones knock out
when Document Setup's Discard White Overprint is on, as in print. Mask art
never overprints. File > Print's composite PDF honours Print > Advanced >
Overprints: Preserve the same way (separations keep multiplying plates).
Each overprinting fill or stroke is drawn as a form marked to overprint
(crates/pdf/src/forms.rs); after writing, its content starts by setting the
overprinting graphics state, and the PDF/X self-check runs on the result.
The engine's "overprint is not written to PDF yet" warning and print's
"overprints print as knockouts in composite output" warning are gone.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Create PDF layers from top-level layers (document.exportPdf createLayers, the
Save PDF dialog's General option) now writes an optional content group per
top-level layer (template layers are left out): named as the layer, off when
the layer is hidden, /PrintState /OFF when its Print option is off, locked
when it is locked, listed top first, with a print auto-state (not under a
standard). The file reopens with those layers.
The PDF writer has no optional content, so each layer is drawn as a form of
its own (no transparency group, so it draws as in place) starting with a mark;
after writing, the uses of the layers' forms are wrapped in /OC ... BDC/EMC
and the catalog gets /OCProperties (crates/pdf/src/forms.rs, through the
shared patch writer and the PDF syntax reader of encrypt.rs). PDF 1.4 and a
knockout page group write plain page content with a warning; the dialog greys
the option at 1.4. The "not written yet" warning is gone.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
skylar taylor-barrick