Print-ready artwork is a file that can go directly to press without any intervention from the printer. It contains everything the press needs: the correct dimensions, the correct colour mode, embedded fonts, sufficient image resolution, and the correct bleed. A file that is not print-ready causes delays, additional prepress charges, and sometimes reprints.
Colour mode: CMYK, not RGB
Commercial printing uses four inks — Cyan, Magenta, Yellow and Black (CMYK). Your monitor displays colour using light — Red, Green and Blue (RGB). These are fundamentally different colour systems, and the range of colours each can produce (the colour gamut) is different. RGB can display colours that CMYK cannot reproduce in print, particularly vivid blues, greens and oranges. If you supply artwork in RGB, the printer's workflow will convert it to CMYK automatically — but automatic conversion may not produce the result you intended. Always convert your artwork to CMYK before supplying it, and check the result after conversion.
Image resolution: 300 dpi at final size
Images in print must be supplied at a minimum of 300 dpi (dots per inch) at the final printed size. A 72 dpi image from a website will look sharp on screen but will print soft and pixelated. A 300 dpi image at 10 cm wide will also print soft if you scale it up to 20 cm — scaling an image up reduces its effective resolution. The rule is: 300 dpi at the final printed size. Check the effective resolution of every image in your layout before supplying the file.
Bleed: 3 mm on all edges
Bleed is the area of artwork that extends beyond the finished edge of the printed piece. It exists because cutting is not perfectly precise — there is always a small amount of variation in where the cut falls. If your artwork has a coloured background or image that extends to the edge of the finished piece, it must extend into the bleed zone. Without bleed, a thin white border will appear on one or more edges of the finished piece. The standard bleed for most commercial print work is 3 mm on all edges.
Safe zone: keep content 3 mm inside the trim
The safe zone is the inverse of bleed. Just as artwork must extend beyond the trim to avoid white borders, important content — text, logos, key design elements — must be kept away from the trim to avoid being cut off. The standard safe zone is 3 mm inside the finished edge. On a small piece like a business card, this is a significant proportion of the total area.
Fonts: embed or outline
Fonts must be embedded in your PDF or outlined (converted to paths) before supplying artwork. If a font is not embedded, the printer's system will substitute a different font, which will change the appearance of your text — sometimes dramatically. In Adobe InDesign and Illustrator, fonts are embedded automatically when you export to PDF using a print-quality preset. To outline fonts in Illustrator: Select All > Type > Create Outlines.
File format: PDF/X-1a or PDF/X-4
PDF is the preferred format for commercial print artwork. Specifically, PDF/X-1a (for jobs without transparency) or PDF/X-4 (for jobs with live transparency) are the industry-standard formats for print production. These formats enforce the requirements above — CMYK colour mode, embedded fonts, defined bleed — and are processed reliably by all professional print workflows. Avoid supplying Word, PowerPoint or Publisher files for commercial printing.
Spot colours: convert or specify correctly
If your design uses Pantone or other spot colours, you need to decide whether to print with spot inks or convert to CMYK. Spot colour printing uses a pre-mixed ink for each colour, which produces more accurate and consistent colour than a CMYK simulation. If you are printing CMYK only, convert all spot colours to CMYK before supplying your file. If you are printing with spot inks, make sure the spot colour names in your file match the Pantone references exactly.
A pre-submission checklist
Before submitting artwork to a commercial printer, work through this checklist: Colour mode is CMYK throughout (no RGB images or objects). All images are at least 300 dpi at final printed size. Bleed extends 3 mm beyond the trim on all edges where artwork reaches the edge. All text and important elements are at least 3 mm inside the trim line. All fonts are embedded or outlined. The file is exported as PDF/X-1a or PDF/X-4. Spot colours are either correctly specified or converted to CMYK. Total ink coverage does not exceed 280% on coated stock or 240% on uncoated stock.