These hairline rules are added during prepress to define the final trim size of a printed piece. They sit outside the live area and guide the bindery operator when setting up the guillotine cutter. When a design bleeds off the edge of the page, the artwork extends past these marks to ensure no white edges remain after trimming.
Heard on the job
The business cards look good, but you forgot to include cropmarks on the PDF, so the bindery will reject it.
Insider tip
Always offset cropmarks by at least an eighth of an inch from the artwork so they do not accidentally show up on the final trimmed piece.
Also heard as
- trim mark
- tick mark