What file format should I use for offset printing?

Submit a print-ready PDF built to press standards. Getting the color mode, resolution, bleed, and fonts right up front is what prevents color shifts and font substitutions once the job runs.

• Format: a flattened, print-ready PDF is the safe standard.
• Color mode: CMYK, not RGB, so on-screen colors translate correctly to ink.
• Resolution: 300 DPI for crisp images and type.
• Bleed: 0.125 inch on all sides for edge-to-edge elements.
• Fonts: outline all fonts to prevent substitution.

A quick prepress check before printing catches most issues, so review your file against these points before you submit.