Print preflight checklist
Last reviewed: 9 October 2026
Printing problems are usually decided before the file ever reaches the press. A short preflight pass — bleed, resolution, colour and fonts — catches the mistakes that otherwise come back as a reprint. This page lists what to check and the values most print shops work to; your printer's own specification always wins.
What preflight is
Preflight is the pass you make over a file just before it goes to print: checking that the geometry, resolution, colour and fonts match what the printing process needs. Done in your design tool it takes a few minutes; skipped, the same mistakes tend to surface as a reprint or an off-colour job.
What to check
The values below are the defaults our own print tools use, plus the conventions most print shops work to. Treat them as a starting point and confirm the numbers with whoever prints your job.
| Item | Typical value |
|---|---|
| Bleed and safe area | 3 mm of bleed on every side is the common default — our bleed tool offers 0, 3 and 5 mm. Keep text and logos a few millimetres inside the trim line. |
| Resolution | 300 DPI for photos and fine detail at final size. Our DPI checker rates 300 as excellent, 200 as good, and 150 as usable only for work seen from a distance. |
| Colour mode | CMYK for print, RGB for screens. Convert before exporting, and expect some shift in very saturated colours. |
| Fonts and fine lines | Embed or subset fonts, or convert them to outlines. Keep hairlines around 0.25 pt or thicker so they do not drop out on press. |
| Page size and imposition | Set the document to the trimmed size plus bleed, and work out the N-up layout before exporting rather than after. |
Common mistakes
These four account for most reprints.
| Mistake | Why it matters |
|---|---|
| Upscaling a low-resolution image | A 72 DPI web image stretched to A4 looks soft on paper. Check the effective DPI at final size, not the pixel count of the file. |
| Sending RGB artwork straight to print | The press converts it for you, and saturated colours can shift. Convert deliberately so you see the result while you can still change it. |
| Text or borders sitting on the trim line | Anything close to the trim can be cut off. Keep important content inside the safe area, not just inside the bleed. |
| Fonts that were never embedded | Missing fonts get substituted, which changes line breaks and spacing. Embed or outline them before export. |
A practical preflight
Work through these in order before you export.
- Set the size and bleed
Set the document to the trimmed size, add the bleed your printer asks for, and keep a safe margin inside the trim line.
- Check resolution at final size
Look at the effective DPI at the size the job will actually be printed, not the pixel dimensions of the exported file.
- Convert the colour
Move images and artwork to CMYK, then check that very saturated colours still look the way you expect.
- Check fonts and fine lines
Embed or outline fonts, and make sure hairlines are thick enough to survive the press.
- Impose and export
Lay the pages up if several go on one sheet, then export a print-ready PDF for your printer.
Common questions
Is 3 mm of bleed always enough?
It is the usual default, but some printers ask for more on large formats or thick stock. Use whatever your printer specifies.
Do I have to use 300 DPI?
300 DPI is the safe value for photos and fine detail at final size. Work that is viewed from a distance can go lower — 150 DPI is often enough for a poster read from a metre away.
Will converting to CMYK change my colours?
It can, especially for bright greens and oranges. The press works in CMYK, so converting before you export means you see the change while you can still fix it.
My printer asks for different values. Which do I use?
Theirs. This page lists common defaults, but the job will be checked against the printer's specification.
Do I need to impose the pages myself?
Only if your printer expects imposed artwork. Many accept single pages and impose in their own workflow, so ask before you spend time on it.
Tools that cover this
These run in your browser and produce drafts you can review before anything goes to a printer.
Where these numbers come from
The bleed and resolution figures are the defaults used by our own print tools, plus the conventions most print shops work to. We are not the authority on your job: the printer's specification decides, and large formats, unusual stocks and special inks all move the numbers.
This checklist is general guidance, not a specification for your job. Confirm bleed, resolution and colour with your printer before you send files.