Trim marks; registration marks

Both live outside the finished piece, in the slug area of the press sheet, and both get thrown away when the job is cut. Trim marks (also called crop marks) are the short right-angle lines at each corner that show the guillotine operator where the final edge is. They sit offset from the trim so the blade never slices through the mark itself, and they only make sense if your bleed extends past them.

Registration marks are the little crosshair-in-a-circle targets. They are drawn in the special Registration swatch, which is built to appear on every separation the job outputs, spot plates included, not just the four process ones. That is the point: the operator can see instantly whether cyan, magenta, yellow, and black are landing on top of each other. If the rings look like a doubled bullseye rather than one clean target, the job is out of register. Printers usually add color bars and a job slug at the same time.

Gotcha: turn these on at export, not by drawing them. Hand-drawn marks sit at the wrong offset, and marks placed inside the page area get trimmed into the design or printed as artwork. Also never use the Registration swatch anywhere in the actual design: on a four-color job it dumps 400 percent ink on the sheet, it smears, and on a job with spot plates it lands on those too. Many modern printers ask for a plain PDF/X with no marks at all, so check the spec before adding them.