Photographic proofs with a distinctive blue colour used to check that elements such as copy and photos are correctly incorporated into a document and to show that folding, trimming, and other bindery processed are correctly understood by the print shop. Also known as dylux, blues, browns, brownlines, silvers, vandykes, and ozalids.
Also referred to as "Blues." This printer's photocopy generated by the printer is a blue-print mock-up of all of the pages of the book printed from the final plates. Bluelines allow a final opportunity to detect errors and make minor corrections before the book goes to press. If changes are needed, they have to be made to the film, which can be expensive.