Charlotte Hughes
There is a particular knot of anxiety that forms when you send a print job off to a commercial press. You have spent hours on the artwork, the colours sing, and the paper stock feels just right. Then the email arrives: the images are too low-resolution, the fonts have shifted, or the colours are off-spec. Now you face a reprint and a delay. Almost every one of these problems can be avoided before you export a file. Here is what to check, and why each step matters.
Start With Resolution
Resolution is the most common culprit behind expensive reprints. In print, it is measured in dots per inch (dpi), and the industry standard for photographic and illustrated work is 300dpi at the final printed size. That last part is crucial: 300dpi at the size the image will actually appear on the page, not the resolution of the file sitting on your hard drive.
Many of us place a web image — typically 72dpi — into a layout and scale it up. At screen size it looks fine, but enlarged to fill half an A4 page the effective resolution plummets. A 72dpi image stretched to three times its original dimensions becomes roughly 24dpi.
- Check effective resolution in your layout software, not just the file size. Most programmes report the dpi at the placed size.
- Aim for 300dpi for photographs and detailed illustrations. Line art and logos often work well at 600–1200dpi.
- Never upscale a low-resolution image; interpolation invents pixels and produces a mushy print. Rescan or re-source instead.
Fonts: Embed or Beware
Fonts are the quiet troublemakers of the print world. Send a PDF without embedded fonts, and the print shop's system substitutes whatever it has on hand. Your elegant serif becomes a generic sans-serif, line breaks shift, and a carefully balanced layout unravels.
Most design software offers an option to embed fonts when exporting a PDF. Take it. If your software lacks the option, convert text to outlines — though be aware that this makes the text uneditable and can increase file size. For home printing the risks are lower, but for anything heading to a commercial press, embedding is the safer route.
- Embed all fonts when exporting. Check the export settings, as some presets disable embedding by default.
- Avoid obscure or system-specific fonts unless you can embed them reliably.
- Keep a copy of the original with editable text so you can make corrections without redoing the layout.
Colour Settings for Home and Commercial Printing
Colour is where home printers and commercial presses diverge most sharply. Screens display colour in RGB, while most commercial printing uses CMYK. Converting between the two is not a simple swap; vivid oranges, deep blues, and neon greens cannot be reproduced in CMYK at all.
If you are printing at home on an inkjet, your printer handles the conversion, but you should still soft-proof your document. Set your software to preview in CMYK and see what shifts. If you are sending files to a commercial press, convert to CMYK yourself and accept that some vibrancy will be lost. The alternative is a surprise on press day.
- Convert to CMYK before export for commercial printing. Leave files in RGB only if the printer asks for it.
- Set your colour profile to match the printer's recommendation; standard profiles are widely available.
- Watch out for rich blacks. Pure black (K only) differs from rich black (a mix of CMYK). Rich blacks look deeper but can cause registration issues on small text.
Bleed, Trim, and Safe Zones
If your design has elements running to the edge of the page — a full-bleed photograph or a coloured border — you need a bleed. Bleed is the extra margin beyond the final trim size that gets cut off after printing. Without it, you risk thin white slivers along the edges where the paper was trimmed slightly off-centre.
A standard bleed is 3mm in the UK, though some printers ask for 5mm. Add this to all four sides. Just as important is the safe zone: keep critical text and logos at least 5mm inside the trim line, so they are not clipped by slight variations in cutting.
- Add 3mm bleed on all sides, or check your printer's specification.
- Keep text within the safe zone — at least 5mm from the trim edge.
- Extend background elements into the bleed area, not just to the trim line.
Exporting and Final Checks
When you export your PDF, choose a print-ready preset rather than a screen or web preset. These handle compression, font embedding, and colour conversion automatically. For commercial work, ask your printer whether they prefer PDF/X-1a or PDF/X-4.
Check the file size too. A well-prepared A4 print file with a few images typically sits between 5MB and 50MB.
Before sending anything to print, run through this checklist. It takes five minutes and can save days of frustration.
- Resolution: all images at 300dpi at final size.
- Fonts: embedded or outlined.
- Colour: converted to CMYK for commercial printing; profiles set.
- Bleed and safe zones: 3mm bleed, 5mm safe margin.
- PDF export: print-ready preset, correct format as requested.
- Proof: print a test copy at home or view a soft proof on screen.
A little preparation goes a long way. Once your files are clean and correctly set up, you can hand them over with confidence — and get back to the part you actually enjoy: making things.
