Producer demo · Trap

Ink-pair trap, in your browser.

Trap compensates for press registration error by overlapping adjacent inks slightly, so a thin white seam doesn't appear at the boundary if the press drifts a hair off. Upload a PDF below — Codex extracts the spot inks, Compile previews the trap zones.

Try it

Drop a PDF (max 25 MB). Codex pre-renders page 1 and resolves the spot inks. When the Compile sidecar is reachable, the trap engine emits a trapped output and a per-pair delta_e_2000 readout. Otherwise you get the input-side facts only — Compile's trap producer is still on its way ( see the implementation plan).

Demo coming soon

The compile-pdf producer engines are still shipping. The demo will activate automatically once they're live.

Request early access

What trap does

Spread. The lighter ink expands a hair into the darker one. Used when the lighter ink is dominant on press.

Choke. The lighter ink contracts a hair away from the darker one. Used when the darker ink wraps the lighter shape.

Direction is derived from neutral-density values that Codex reads off the input — Compile never re-implements that math.

Engine slots

pure_python — default. Uses codex_pdf.geom.polygon_offset + the color resolver. Bit-deterministic.
ghostscript — bootstrap fallback, gated by the [trap-gs] extra.
external — Esko / Heidelberg vendor integration, gated by [trap-external].

Codex surfaces consumed

codex_pdf.color.CodexSpotIntent
codex_pdf.color.resolve_spot_swatch_color
codex_pdf.color.delta_e_2000
codex_pdf.geom.polygon_offset

Spread vs choke at a glance

Spread. The lighter (lavender) ink overlaps a sliver into the darker.

Choke. The darker ink wraps a sliver of the lighter's edge.

Privacy

Demo files are processed in memory. The Codex pre-render and computed SHA-256 are kept up to one hour for replay; trap-diff lineage records are kept up to thirty days. No file content is shared with third parties.