pdfpressWhy Your 85 × 55 mm Card Finishes at 79 × 49 mm
Two controls are both called bleed and they do opposite things. One says how much bleed your artwork already carries; the other adds bleed that was not there. Getting them the wrong way round shrinks your finished size by twice the bleed.
The symptom: cards that trim 6 mm small
You set up 85 × 55 mm business cards, switched bleed on at 3 mm, sent the sheet to the guillotine, and the cards came back 79 × 49 mm. Nothing warned you. The preview looked right. The crop marks were exactly where the software said they would be — 79 mm apart.
Six millimetres is exactly twice the bleed. That is the tell, and it is not a bug: the software did precisely what you told it. The problem is that you and it disagreed about what the bleed number meant.
Two controls, one word, opposite directions
Almost every prepress application has two features that both use the word bleed, and they run in opposite directions.
- Bleed the artwork already carries. This is what an imposition tool asks about. Your page is 91 × 61 mm of ink, of which the outer 3 mm on each side is bleed that gets cut away. The finished piece is 85 × 55 mm. The tool needs to know about that margin so it can place the trim, not the ink, on a grid — and so the crop marks land on the cut line rather than 3 mm outside it.
- Bleed that needs creating. This is what an add bleed tool does. Your page is 85 × 55 mm with ink right to the edge and no margin at all. The tool mirrors or stretches the outer pixels to invent 3 mm of bleed, and the page becomes 91 × 61 mm. The finished size does not change — you have added material to cut off, not taken material away.
The arithmetic on the imposing side is the whole article:
trim = placed size − 2 × bleed
Declare 3 mm of bleed on an 85 × 55 mm page and you have told the software that only the inner 79 × 49 mm is the product. It believes you. It sets the marks accordingly.
Which one do you actually need?
Open your PDF and ask one question: is there ink outside the finished size?
| What your file looks like | What you need | Bleed value when imposing |
|---|---|---|
| 91 × 61 mm page, design is 85 × 55 mm with 3 mm of ink running past it | Nothing — it is already right | 3 mm |
| 85 × 55 mm page, ink stops at the edge, white border | Nothing — it has no bleed and does not need any | 0 mm |
| 85 × 55 mm page, ink runs to the very edge | Add bleed first, then impose | 3 mm, after adding it |
| Page carries a real TrimBox and BleedBox | Nothing at all | Leave it — the boxes already say |
That last row is worth dwelling on. A PDF exported properly from a layout application carries its own box geometry: a MediaBox for the sheet, a TrimBox for the finished size, a BleedBox for the ink beyond it. When those boxes are present, no number is needed, and typing one anyway is how the mistake happens. Good imposition software reads the boxes and ignores you.
How PDF Press handles it
The two controls are deliberately not called the same thing.
- On N-up, Step & Repeat and Cut & Stack, the field is Bleed in art. It describes the file you brought.
- On Add Bleed, the field is Bleed to add, and its description says plainly that the finished size does not change.
And when the two disagree with what you probably expect, the panel says so before you export rather than after you cut. Set 3 mm of bleed in art on an 85 × 55 mm page and the summary reads:
10 per sheet on A4 · 2 × 5 · finishes 79 × 49 mm
That clause only appears when the finished size differs from the page you brought in — which is exactly the case where somebody is about to be surprised. If your file already carries a BleedBox, the trim is untouched and the note stays quiet.
The gap between neighbours, and the bleed you actually get
There is a second place bleed surprises people, and it shows up on the same sheet.
When pieces with bleed sit next to each other, their bleeds run into each other. A grid steps by the trim plus the gap, so with a 5 mm gap and 3 mm of bleed, the two bleed zones overlap by 1 mm. The knife cuts once, down the middle, and each piece ends up with 2.5 mm of bleed — not the 3 mm you specified.
This is the normal shared-cut convention and it is not a defect: it is how you fit more work on a sheet. It only becomes a problem when nobody tells you, because 2.5 mm is fine and 0.5 mm is not, and you cannot tell which you have without doing the arithmetic. With a 0 mm gap, adjacent pieces get no separate bleed at all — they share one cut line and the ink simply continues from one piece into the next.
PDF Press states the delivered figure rather than the requested one:
· neighbours share the cut · 2.5 mm each side
If you need the full 3 mm on every piece — some finishers insist on it, particularly for anything die-cut afterwards — open the gap to at least twice the bleed. At 6 mm the zones meet exactly and nothing is shared.
A 30-second check before you send the sheet
- Measure the finished size in the summary, not the page size in the panel. If it does not match what the client ordered, the bleed number is wrong.
- Measure between crop marks in the output. They sit on the trim line. Marks 79 mm apart mean a 79 mm card, whatever your artboard said.
- Check the gap against twice the bleed. Narrower means a shared cut and less bleed per piece than you asked for.
- If the file has real boxes, leave the number alone. Overriding correct geometry with a guess is the most common way to lose 6 mm.
Frequently Asked Questions
Why did my 85 × 55 mm card come out 79 × 49 mm?
Does adding bleed change my finished size?
My PDF has a TrimBox. Do I still set a bleed value?
Why is my bleed only 2.5 mm when I asked for 3 mm?
What happens with a 0 mm gap?
Ready to put this into practice?
Do it in your browser — the sheet, the count and the marks are set for you. Change only what you want.
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