The owner's 2026-08-08 report ("SF symbols don't render well in the PDF output
of File ▸ Print…") photographed solid dark rectangles where the card icons
belong. The cause is not typography and not the renderer's layout: an
`NSImage(systemSymbolName:)` is a *template* image, a shape meant to be tinted
by the AppKit machinery that draws it. A print/PDF context has none of that
machinery, so the tint lands on the image's whole box instead of through its
coverage — a filled rectangle, measured at 1.000 ink coverage through a real
`NSPrintOperation`.
A second failure hid behind the first: a PDF context is a 1× device, so even a
non-template symbol rasterized at 72 ppi on the way onto the page (13 × 12
pixels for an 11 pt icon) and blurred at any zoom.
Both are the same mistake — leaving work for a context that cannot do it — so
`PrintSymbol` does the work first: the symbol is inked in the line's own colour
(resolved against the paper appearance, since a dynamic colour resolves at draw
time and this drawing happens long before the page exists), drawn into a bitmap
at eight times the point box, and handed over as ordinary non-template artwork.
The page now carries a 576 ppi glyph at 0.277 coverage. True vector was
measured and is not available: `NSSymbolImageRep` rasterizes into whatever
context draws it, the symbols are not reachable as font glyphs by name, and
re-wrapping the image in a PDF representation only embeds the same raster one
level down.
While in there, the attachment's baseline stops being a guess. It was
`font.descender * 0.5` — a constant that knew nothing about which symbol it was
placing, so every icon floated by a different amount. It is now the symbol's own
`alignmentRect`, which is Apple's metric for exactly this: the rect's height is
the font's cap height and its origin is the symbol's baseline within its box.
The forced light appearance moves to `PrintTypography.paper` because two places
now depend on it and must not drift: the page view pins it, and the symbol
raster draws under it.
Lane headings were checked and need nothing — `PrintLane` carries no icon, so
card meta lines are the only symbols a printed document has.
Tests drive the real pipeline: `PrintDocumentBuilder` → `PrintDocumentRenderer`
→ a real `NSPrintOperation` to PDF, then measure the ink on a sheet whose only
content is one icon. The coverage assertion fails at 1.000 on the shipped build.
Claude-Session: https://claude.ai/code/session_014PtZdPwqZuqEDLc6wZMtEy
rzen
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