verify-bleed-safe

Verify Bleed-Safe

Inspect a PDF and report any pages where content extends into the printer's unprintable margin (typically 3–6mm from each edge for office laser/inkjet printers).

This is a read-only preflight check. It modifies nothing — it only reports.

Inputs

• Input PDF path (required).
• Safe margin (optional, mm) — default 5mm. The minimum distance from page edge that content must respect.
• Per-edge override (optional) — top=X bottom=Y left=Z right=W if the printer's unprintable margins are asymmetric.

How it works

For each page:

1. Get the page MediaBox: pdfinfo -box input.pdf or mutool show input.pdf trailer.
2. Compute the "safe box" = MediaBox shrunk by the safe-margin on every side.
3. Get the bounding box of all content on the page (text + images + vector). Use gs -sDEVICE=bbox for the ink-bbox of each page:

   gs -dQUIET -dBATCH -dNOPAUSE -sDEVICE=bbox input.pdf 2>&1 | grep "%%HiResBoundingBox"
   

4. Compare content bbox against safe box. If content extends past the safe box, report:
   • Page number
   • Which edge(s) violated
   • How far the violation extends (mm)

Output

Plain-text report:

Bleed-safe check: input.pdf (safe margin: 5mm)

PAGE 1: OK
PAGE 2: VIOLATION — text extends 2.3mm past the right edge safe zone (content bbox: ..., safe box: ...)
PAGE 3: OK
PAGE 4: VIOLATION — image extends 8.1mm past the bottom edge safe zone
...

Summary: 2 of 12 pages have bleed-safe violations.

Suggest remedies in the report:

• For minor overruns (<10mm): rerun source layout with larger margins, or scale page contents down via gs -dPDFFitPage.
• For consistent overruns: the document may have been laid out for a printer with smaller unprintable margins — ask the user.

Tooling

• ghostscript — bounding-box detection.
• pdfinfo (poppler-utils) — page dimensions.
• mutool (mupdf-tools) — alternative geometry probe.

Notes

• This check is about fit-within-printable-area. It does not address commercial-print bleeds (where you want content to extend past the trim line). For that, use add-bleed.
• Violations don't always mean the print will fail — they mean it might clip. The printer's exact unprintable margin varies by model. 5mm is a safe default; tune for known printers.