| name | add-bleed |
| description | Add bleed margins to a PDF for commercial print shops that trim — extends the page size by the bleed amount on each side and shifts content to the new center. Most office digital printing does NOT need this; use only when sending to a print shop. Triggers on phrases like "add bleed", "add 3mm bleed", "prep for trim". |
Add Bleed
Expand a PDF's page size to add bleed on every side. Commercial print shops trim to the trim line; the bleed area absorbs registration error.
When to use
- Sending to a commercial / offset / print-shop digital press that trims final size.
- Document has edge-to-edge images or color that should extend past the trim.
When NOT to use
- Office laser/inkjet printing — these don't trim, and printing onto a larger page just wastes paper or fails.
- Standard documents with white margins — bleed adds nothing.
Inputs
- Input PDF path (required).
- Bleed amount (optional, mm) — default 3mm (industry standard). Some shops want 5mm.
- Output path (optional) — defaults to
<input>-bleed.pdf.
Tooling
pdfjam or ghostscript. Strategy: increase MediaBox by 2 × bleed on each axis, then shift content by bleed so it remains centered.
Recipe (ghostscript)
gs -o output.pdf \
-sDEVICE=pdfwrite \
-dDEVICEWIDTHPOINTS=612 \
-dDEVICEHEIGHTPOINTS=859 \
-dFIXEDMEDIA \
-c "<</PageOffset [8.5 8.5]>> setpagedevice" \
-f input.pdf
Caveats
- This skill does not extend background images/colors into the bleed area — it just adds whitespace. If the source layout has edge-to-edge images, those need to be redesigned with bleed at the source (Indesign, Affinity, etc.). Adding bleed after the fact on an already-laid-out PDF leaves a visible white band around content.
- For source-correct bleed, redo layout with bleed enabled in the design tool. This skill is a last-resort prep.
Output
Bleed-extended PDF.
