Every print shop has the same story: a job arrives, the files look beautiful on screen, and prepress sends it straight back. Missing bleed. RGB photos. A logo built in spot colours that nobody ordered. A 72 ppi image scaled to 400%. None of these are design mistakes, they are file preparation mistakes, and they cost you time, money and sometimes a whole reprint.
This pre press checklist is written from the other side of the counter. For each of the 12 checks below you get the error we actually see, why it breaks on press, and the exact setting to fix it in Adobe InDesign and Adobe Illustrator. Work through it before every upload and your rejection rate drops to close to zero.
The 12-point pre press checklist at a glance
| # | Check | Target value |
|---|---|---|
| 1 | File format | PDF/X-4 (or PDF/X-1a if asked) |
| 2 | Document size | Exact finished trim size, single pages |
| 3 | Bleed | 3 mm / 0.125 in on all four sides |
| 4 | Safety margin | 3 to 5 mm inside the trim |
| 5 | Colour mode | CMYK with the supplied ICC profile |
| 6 | Spot colours | Only the ones you are paying for |
| 7 | Image resolution | 300 ppi effective at final size |
| 8 | Blacks and ink limit | 100K text, rich black for large areas, TAC under 300% |
| 9 | Overprint | No accidental overprint on white or light objects |
| 10 | Fonts | Fully embedded, or outlined as a last resort |
| 11 | Thin lines and small type | 0.25 pt minimum, 6 pt minimum reversed type |
| 12 | Preflight and packaging | Zero errors, clean file name, links collected |
1. Export the right file format
A packaged InDesign folder is fine for archiving, but presses run on PDF. Unless your printer asks for something else, export a PDF/X-4: it keeps live transparency, supports colour management and is what modern RIPs expect. PDF/X-1a is still requested by some older workflows because it flattens transparency and converts everything to CMYK.
InDesign
File > Export > Adobe PDF (Print) > preset [PDF/X-4:2010]. Do not use “Smallest File Size”, it downsamples images to 100 ppi and can strip profiles. Preflight checklist to ensure great printing results tackles the same question from another angle.
Illustrator
File > Save a Copy > Adobe PDF > Adobe PDF Preset [PDF/X-4:2010]. Untick “Preserve Illustrator Editing Capabilities” so the file size stays sane.
2. Build the document at the finished trim size
We see A4 artwork placed on an A3 page “so you can see the bleed”. That is not bleed, it is a second trim box the RIP will fight with. Your page size must equal the finished size after cutting.
- Supply single pages, in reading order, not reader spreads. Imposition is our job.
- Covers for perfect-bound books are the exception: supply them as one flat spread including the spine width we give you.
- Keep the orientation consistent across all pages of the same document.
Check in Acrobat with Print Production > Set Page Boxes, or simply hover: the TrimBox should match your sold size exactly, the MediaBox should be larger by the bleed plus marks.
3. Add bleed, properly
Anything that touches the edge of the page must extend 3 mm (0.125 in) past the trim line. Guillotines and folders have tolerance, and without bleed you get a white sliver on one edge of half the run.
| Product | Recommended bleed |
|---|---|
| Business cards, flyers, leaflets | 3 mm |
| Perfect-bound covers, hardbacks | 5 mm plus wrap allowance |
| Die-cut packaging and labels | 3 to 5 mm beyond the cutter guide |
| Large format, banners | 10 mm, more if hemmed or eyeleted |
InDesign
File > Document Setup > Bleed and Slug, enter 3 mm on all sides. At export, Marks and Bleeds > tick Use Document Bleed Settings. Also extend the images themselves, a bleed box with nothing in it does nothing.
Illustrator
File > Document Setup > Bleed, 3 mm all round. At save time tick Use Document Bleed Settings. Remember Illustrator does not clip to the artboard by default, so pull background shapes to the bleed line rather than leaving them floating 20 mm outside.
4. Respect the safety margin
Keep all text, logos, page numbers and anything you would hate to lose at least 3 to 5 mm inside the trim, and more for bound products where the gutter swallows content. For saddle-stitched booklets, allow for creep on inner pages. For perfect binding, keep live matter 10 mm away from the spine fold.
5. Convert to CMYK with the right profile
RGB images do not fail, they simply print differently from what you approved on screen. The bright blue that glowed on your monitor becomes a flat purple-grey. Convert deliberately rather than letting the RIP guess.
- Ask your printer which ICC profile applies: typically a coated FOGRA/PSO profile for sheetfed in Europe, GRACoL for US sheetfed, or a web/uncoated profile for newsprint style stocks.
- Set it in Edit > Colour Settings in both InDesign and Illustrator so new documents inherit it.
- At export, Output > Colour Conversion: Convert to Destination (Preserve Numbers), Destination = the supplied profile, Profile Inclusion Policy = Include Destination Profile.
“Preserve Numbers” matters: it stops a pure 100K black from being re-separated into a muddy four-colour black.
6. Clean up your swatches and spot colours
A four-colour job with a stray Pantone in the swatch panel will either separate to a fifth plate and be quoted again, or get converted at random. Open the Swatches panel and delete everything unused (Swatches menu > Select All Unused > delete).
- If the job is CMYK only, convert every spot to process: select the swatch, Swatch Options, Colour Type = Process.
- If you genuinely need a spot, name it exactly as the printer expects, for example PANTONE 2935 C, and use the identical name in InDesign, Illustrator and any placed logo.
- Finishing layers (spot UV, foil, varnish, die line) must be a single named spot swatch, set to 100% overprint, on their own top layer, and listed in your order notes.
Verify in Acrobat Pro: Print Production > Output Preview, then read the separations list. What you see there is exactly what we will plate. Related reading: Print Checklist: How to Prepare Files for Press.
7. Check effective image resolution, not file resolution
A 300 ppi photo enlarged to 200% is a 150 ppi photo. InDesign tells you the truth: Window > Output > Links, and look at Effective PPI, not Actual PPI.
| Job type | Minimum effective resolution |
|---|---|
| Offset and digital sheetfed | 300 ppi |
| Newsprint | 200 ppi |
| Bitmap line art and scanned signatures | 1200 ppi |
| Posters viewed at 1 to 2 m | 150 ppi |
| Banners viewed at 5 m or more | 72 to 100 ppi |
Other image traps we catch weekly: screenshots and web JPEGs, logos pulled from a website instead of the vector original, and PNG files with transparency plus a drop shadow that flattens into a grey box. When a vector version of a logo exists, use it.
8. Control your blacks and total ink coverage
This is the check that separates amateurs from production-ready designers.
- Body text and small type: 100% K only. Four-colour text shows registration fringes on press.
- Large black panels: rich black, a common recipe is 60C 40M 40Y 100K. Flat 100K alone looks washed out over a big area.
- Total Area Coverage: keep under about 300% for coated sheetfed, 240 to 260% for uncoated or web. Above that, ink does not dry, sheets set off and you get ghosting.
- Never use “Registration” black for anything except crop marks. It is 400% ink.
Check it in Acrobat Pro: Output Preview > Total Area Coverage, enter your limit and the hotspots light up.
9. Kill accidental overprint
Overprint tells the press not to knock out what is underneath. Set on purpose it is useful, usually for black text or a varnish layer. Set by accident, usually inherited from an old logo or a careless Attributes click, it makes white objects disappear completely on the printed sheet while still looking fine on your screen.
How to find it
- InDesign and Illustrator: View > Overprint Preview. If anything vanishes or changes colour, you have a problem.
- InDesign: select the object, Window > Output > Attributes, untick Overprint Fill and Overprint Stroke.
- Illustrator: Window > Attributes, same two tick boxes. Or Edit > Edit Colours > Overprint Black to apply it deliberately.
- Rule to remember: white should never overprint. White set to overprint prints as nothing.
10. Embed fonts, outline only when you must
PDF/X requires embedded fonts, and embedded is better than outlined: outlining destroys hinting, can shift small text slightly, and makes last-minute typo corrections impossible. Outline only when a font licence blocks embedding, or when you are supplying a cut file for vinyl or die-cutting.
- InDesign: Type > Find Font shows every family in use and flags missing ones. Fix missing and modified links before export.
- Illustrator: Type > Find Font, then if needed Select > All and Type > Create Outlines (Shift+Ctrl+O). Watch for text inside symbols and clipping groups, they are often missed.
- Verify after export: in Acrobat, File > Properties > Fonts. Every entry should say “Embedded” or “Embedded Subset”.
- Avoid fake bold and fake italic applied from a toolbar button, they can drop out at the RIP. Use the real weight.
11. Mind hairlines, small type and reverse-outs
Fine detail that survives your laser proof can disappear on press or plug up on uncoated stock.
- Minimum stroke weight: 0.25 pt. Never use the “Hairline” setting, it is device dependent.
- Reversed white type: minimum 6 to 7 pt, and keep it a single-colour background wherever possible.
- Avoid multi-colour rules thinner than 0.5 pt, registration variation will show.
- If you scale artwork in Illustrator, enable “Scale Strokes & Effects” or your 0.25 pt line becomes 0.05 pt.
12. Preflight, package and name the file sensibly
Run the software checks before we run ours.
InDesign
- Window > Output > Preflight, and build a profile that flags RGB, missing links, images under 300 ppi, overset text and non-proportional scaling.
- File > Package collects the document, fonts, links and a report in one folder. Send this if the printer asks for native files.
Illustrator
- File > Package does the same job, including linked images and fonts.
- Window > Document Info > Objects for a quick audit of spot colours, patterns and placed images.
Acrobat Pro
- Print Production > Preflight > Prepress profiles. Run the PDF/X compliance check and a “Digital printing and online publishing” or sheetfed profile.
- Finish in Output Preview: separations, ink coverage, object inspector.
File naming
Use something a stranger can identify at 7 am: ClientName_Job_A5-Flyer_v3_PRINT.pdf. Avoid spaces, accents, slashes and “final_final2”. Supply one PDF per component (cover, text, insert) rather than everything merged.
Copy and paste pre press checklist
Keep this version next to your keyboard or paste it into your project template.
- Page size equals finished trim size, single pages, correct orientation
- 3 mm bleed set in Document Setup and artwork actually extends into it
- All live matter 3 to 5 mm inside the trim, gutter allowance added
- Document and all images converted to CMYK with the supplied ICC profile
- Swatch panel cleaned, unused spots deleted, required spots named correctly
- Every link present, up to date, 300 ppi effective, no PNG or web JPEG
- Text in 100K, rich black used for panels, total ink under 300%
- Overprint Preview checked, no white or light object set to overprint
- Fonts embedded or outlined, no fake bold or italic
- Strokes 0.25 pt or heavier, reversed type 6 pt or larger
- Preflight clean in InDesign or Illustrator, then in Acrobat Pro
- Exported as PDF/X-4 with crop marks, 3 mm offset, document bleed included
- File named clearly and proof approved by the client in writing
Export settings cheat sheet
| Export panel | Setting |
|---|---|
| General | Preset PDF/X-4:2010, Pages (not Spreads) |
| Compression | Colour and greyscale: Bicubic Downsampling to 300 ppi for images above 450 ppi, JPEG Maximum or ZIP |
| Marks and Bleeds | Crop marks on, weight 0.25 pt, offset 3 mm, Use Document Bleed Settings |
| Output | Convert to Destination (Preserve Numbers), destination profile from printer, include profile |
| Advanced | Subset fonts below 100%, Transparency Flattener High Resolution if a PDF/X-1a is requested |
The five errors that cause most rejections
- No bleed, or bleed box set but artwork not extended
- RGB or mixed colour spaces, often hidden inside a placed PDF or an Illustrator logo
- Low effective resolution from enlarged images
- Unwanted spot colours creating an extra plate
- Accidental overprint on white elements
Fix those five and you have eliminated the large majority of prepress callbacks. Work the full 12-point list and your files go straight to plate.
FAQ
What is prepress exactly?
Prepress is every step between a finished design and the press starting: file checking (preflight), colour conversion, trapping, imposition, proofing and plate or RIP output. A pre press checklist is the designer’s share of that work.
Should I send PDF/X-1a or PDF/X-4?
PDF/X-4 for most modern workflows, because it preserves live transparency and ICC colour management. Use PDF/X-1a only when your printer specifically asks for it, usually for older RIPs that need flattened transparency and pre-converted CMYK.
Is 3 mm bleed always enough?
For standard trimmed sheet work, yes. Increase to 5 mm for bound covers and die-cut packaging, and to 10 mm or more for large format, banners and anything wrapped around a frame.
Do I have to outline all my fonts?
No. Embedded fonts in a PDF/X file are safer and keep the text editable for last-minute corrections. Outline only when the licence prevents embedding or when you are supplying cut paths.
How do I check ink coverage without Acrobat Pro?
Use the Separations Preview in InDesign (Window > Output > Separations Preview) and switch to Ink Limit, then set your maximum, typically 300%. Areas above the limit are highlighted. The piece checklist for a perfect PDF for printing makes a good next read.
Can I just send my InDesign file?
Only if you package it, with fonts and links included, and only if your printer accepts native files. A PDF/X is always faster to process and removes any risk of missing fonts or substituted links.
Why do my colours look different from my screen?
Monitors emit light in RGB, presses lay ink in CMYK on an absorbing substrate. Soft proof with the correct ICC profile (View > Proof Setup in InDesign) and request a contract proof for any job where colour accuracy is critical.
Need a second pair of eyes? Send your files over and our prepress team will run a full preflight before anything goes to plate. Spotting a problem at file stage costs nothing. Spotting it on 5,000 printed sheets costs a reprint.