Illustrator 30.0's gradient Dither, from the public documentation
(https://helpx.adobe.com/illustrator/desktop/paint-and-fill/create-and-edit-gradients/control-dither-in-gradients.html):
a Dither checkbox in the Gradient panel; dither converts the gradient into
pixels with subtle noise, works with gradient fills only, and follows the
Document Raster Effects resolution.
- Gradient gains `dither` (serde default false, written only when on, so
older files open unchanged and new files keep it).
- The renderer draws a dithered linear or radial fill as an image paint: the
gradient sampled a cell per device pixel or finer (quarter-octave steps,
cached per thread), each channel given seeded triangular noise of up to a
level before rounding. Same pixels every run; strokes and undithered fills
draw exactly as before. PNG and other raster exports go through it.
- SVG and PDF write a dithered fill as an image at the document's raster
effects resolution, clipped to the shape (the freeform-gradient path);
characters' fills stay vector gradients in SVG, with a warning.
- paint.editGradient and paint.setFill take `dither`; strokes refuse it.
The Gradient panel's Dither box is dimmed behind the Stroke proxy.
- i18n rows in all 24 catalogs; docs: G13, target-app-parity, ui-parity,
mcp.md, plugins.md.
Radial gradients show a dashed extent ellipse: its handle across the bar
sets the aspect ratio, the ellipse elsewhere rotates it, and the dot inside
the centre ring drags the focal point (GradientGeom.focal) for an off-centre
radial. paint.setGradientGeom takes aspect (%) and focal ([x,y] | null), and
start/end may be left out; the focal point keeps its place in the ellipse as
the vector, aspect and object transform. It renders as a two-point radial,
exports and imports as SVG fx/fy and PDF two-point radial shadings, expands
to off-centre rings, and travels in gradient params and the native format.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Colours gain a CIE Lab model (`Color::Lab {l,a,b}`, serde tag `lab`), handled through the
CMS (display, separation, conversions, gamut), tints (toward paper white), keep_model, harmonies,
recolouring, blends, Info and the Color panel. Swatch Options gets a Lab mode
(`swatch.edit {mode: "lab"}` / `{color: {l,a,b}}`), and colour params accept `{l,a,b}`.
Swatches panel → Spot Colors… (`ui.spotColors`, dialog `spotColors`) runs `swatch.spotOptions
{useLab}` (Document.spot_use_lab, default on): Lab spot colours show and separate from their Lab
values, or art linked to them takes their working-CMYK equivalents, as one undo step. PDF export
writes Lab spot inks as Separation spaces with a Lab alternate (tint function from paper white),
or a DeviceCMYK one with CMYK equivalents.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Applying a gradient swatch records it as the gradient's swatch (the Swatches panel highlights
it and the Gradient panel's swatch menu marks it). A stop given a global or spot swatch (and a
tint) in paint.editGradient / a gradient paint's stops, dropped from the Swatches panel or
picked in the stop popover stays linked: editing the swatch recolours it, in art and in
gradient swatches, deleting it unlinks it. Spot stops separate on their plate, and a gradient
whose stops are all tints of one spot ink (or paper white) exports to PDF as a Separation
shading; gradients mixing models are written in one colour space (the PDF writer requires it;
mixed models used to abort the export).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Freeform gradients carry their own points (colour, opacity, spread) and lines
(Catmull-Rom curves through points), blended by inverse-distance weighting
from each disc of pure colour. paint.editGradient {kind: "freeform", mode?}
places 4+ points inside the shape, coloured along the stops (which follow the
points' colours). The renderer samples the field on a cached colour grid
drawn as an image paint clipped by the fill or stroke. Moves, transforms,
box rebases and warps move the points; old files load unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Taha-Mahmoodi