Designing for Print: The File Preparation Checklist

Why File Prep Matters

Design software and printing equipment speak different languages. A file that looks perfect on screen can produce a failed print job if it hasn't been prepared correctly for the printing process. The gap between screen and print is closed through proper file preparation.

This is production craft, not glamorous. But it's the difference between a good print and a bad one.

The Checklist

Color mode: All files intended for print should be in CMYK unless spot colors are being used, in which case colors should be specified as appropriate spot color libraries. RGB files sent to offset printers will be converted, often with unexpected color shifts.

Resolution: Raster images should be 300 DPI at the final print size. Images that are 300 DPI at a smaller size become lower resolution when scaled up — check the actual resolution at the print dimensions, not at the placed size.

Bleed and safe zones: Files destined for trimmed print pieces need bleed — typically 3mm on all sides extending beyond the trim edge. Content that should not be cut must be within the safe zone (typically 3-5mm inside the trim edge).

Fonts: All fonts should be outlined or embedded. Sending a file with live type using fonts the printer doesn't have will cause font substitution with unpredictable results.

Overprinting: Check that black text is set to overprint (so it doesn't knock out the background) and that white elements are set to knockout (so they don't overprint and disappear on dark backgrounds). Overprint preview in Illustrator and InDesign lets you verify this before output.

Spot colors: Any spot colors should be correctly named to match the print specification. Pantone swatches that are RGB-mode rather than spot-color mode will be converted to CMYK on print.

Image links: All placed images should be linked, at full resolution, and packaged with the file. Missing links will fail at output.

PDF export settings: For offset printing, PDF/X-1a or PDF/X-4 are standard exchange formats. Verify that the PDF export preset matches what the printer has requested.

The Preflight Check

InDesign and Illustrator both include preflight tools that check for common production errors before output. Run the preflight before sending files. Fix every flagged issue.

Communication with the Printer

Unclear about any specification? Ask the printer before sending. Reprints due to preparation errors are expensive. A ten-minute call before production saves hours of problems after.