A printer will usually print exactly what you send. If the resolution is low, the ink is low-resolution too. If a font is missing, something else gets substituted. Almost every expensive print mistake is something that was visible in the file beforehand and nobody looked. This is the check that catches them.
Resolution: 300 DPI at final size
Print needs roughly 300 dots per inch at the size the piece will actually be. The catch is "at final size" — an image that is 300 DPI on a business card is 75 DPI when the same file is stretched across an A4 poster, and it will look soft.
The arithmetic is simple: multiply the printed size in inches by 300. An A4 page is 8.3 × 11.7 inches, so a full-bleed image needs to be around 2500 × 3500 pixels. Anything smaller is being enlarged, and enlarging cannot add detail that was never captured — a point worth remembering when a client sends a logo pulled off their website.
Large-format work is the exception. A billboard is viewed from far enough away that 30 to 50 DPI is fine, and printing one at 300 would produce a file nobody could open. Ask the printer what they want rather than assuming.
Bleed and safe margins
Paper shifts slightly as it is cut, by a millimetre or two. If your background stops exactly at the trim line, that shift leaves a thin white sliver along one edge — the single most common reason a job is reprinted.
The fix is bleed: extend any colour or image that touches the edge about 3mm past the trim line, so there is material to cut into. Then keep text and logos at least 3 to 5mm inside the trim line, in what printers call the safe area, so the same shift does not clip them.
Set both up in the document before you start designing. Adding bleed to a finished layout usually means stretching backgrounds awkwardly or rebuilding the edges.
Colour mode and the colours that will not survive
Send CMYK unless the printer asks otherwise. If you send RGB, it gets converted anyway, and you will not be the one choosing how. The colours most likely to shift are exactly the ones people care about: bright orange, vivid green, electric blue and pure saturated red all sit outside what standard ink can produce.
Rich black is worth knowing about too. Pure black set as 100% K prints as a slightly washed dark grey over large areas. For large solid blacks, most printers prefer a rich black mix — something like 60C 40M 40Y 100K — but never use rich black for small body text, where the four plates cannot align precisely enough and the text looks fuzzy.
Fonts, links and flattening
A font that lives on your machine does not travel with the file. If it is not embedded, the printer's system substitutes something else and the layout reflows — often without anyone noticing until it is printed. Exporting to PDF with fonts embedded solves this. Converting type to outlines is the belt-and-braces version, though it makes later text edits impossible, so keep an editable copy.
Check linked images are actually linked and up to date, not missing or pointing at a low-resolution placeholder from an early draft. Most layout software will warn you; it is worth reading the warning rather than clicking through it.
File format and final checks
Press-ready PDF is the standard, usually PDF/X-1a or PDF/X-4 depending on the printer. Ask which they want. Send one file with pages in reading order rather than a folder of separate images — if you have several pages as separate exports, merging them into one PDF in the right order takes a moment and removes a whole category of confusion.
Then check the PDF itself, not the layout file: open it, look at every page at 100%, confirm the page count and orientation, and confirm nothing is rotated. A page that opens sideways will often print sideways, and fixing the stored rotation before sending is a one-minute job.
Finally, ask for a proof. A digital proof catches layout and content errors; a physical proof catches colour. On anything with a meaningful print run, the cost of a proof is a fraction of the cost of reprinting.
Common questions
What resolution does print artwork need?
Around 300 DPI at the final printed size for anything held in the hand — flyers, brochures, packaging and business cards. Large-format work viewed from a distance, such as banners and billboards, is usually fine at 30 to 50 DPI. Check the size in inches and multiply by the DPI to get the pixel dimensions you need.
How much bleed should I add?
Three millimetres past the trim line on every edge that carries colour or imagery is the common standard, though some printers ask for five. Keep text and logos at least three to five millimetres inside the trim line as well, so that normal cutting variation cannot clip them.
Should I send RGB or CMYK to a printer?
CMYK, unless the printer specifically asks for RGB. Files sent in RGB get converted regardless, and the conversion is then out of your hands. Converting yourself lets you see which colours shift and adjust them before anyone prints thousands of copies.
Do I need to convert text to outlines?
Not if fonts are properly embedded in the exported PDF, which is the usual approach. Outlining is a safeguard for unusual fonts or awkward workflows, but it makes the text uneditable, so always keep an editable version of the file alongside it.
Last updated 2 September 2026