prepress

Prepress is the stage in printing and publication production that prepares digital content for printing. It encompasses the conversion of design files into printer-ready data, color management, page layout, image processing, typesetting, and the creation of proofs. The goal is to ensure that the final printed product matches the designer's intent within the constraints of the chosen printing process.

Typical workflow includes file preparation, color management, trapping and screening, imposition, and plate or plate-less imaging. Designers supply source files (often in PDFs or native formats); prepress converts and optimizes them for the press. Color management uses ICC profiles to maintain consistent colors across devices; color separations for CMYK or additional inks are generated as needed. Proofing and verification are important steps: soft proofs viewed on monitors and hard proofs or contract proofs used to authorize the run. Proofs check layout, color accuracy, trapping, and font embedding. Imposition arranges pages for efficient printing and binding, and trapping reduces gaps due to misregistration. In modern workflows, most prepress is digital, using RIP software to rasterize pages for the press.

Output and media: final files may include press-ready PDFs (e.g., PDF/X-1a, PDF/X-4), accompanied by specifications for ink, substrate, and finish. On-press plate making (offset) or direct-to-plate systems are common. Prepress also handles archival of source files and production notes for repeatability and quality control.