What are Crop Lines?
Lines on a layout that indicate where the printed piece is to be trimmed.

What do I need to Know about Crop Lines?
When designing a full bleed document your design should extend 1/8 of an inch BEYOND the crop lines. That said, it is important that no text or important graphics extend to the crop line. You need 1/8 of an inch BEFORE or INSIDE the crop line to prevent important text or images from being cut. Sound Confusing? It's not. Simply be sure to extend your design to the edge of the page (if full bleed), but don't include anything of vital importance any closer than 1/4 of an inch from the edge.