This only applies to designs where the image or background pattern extends to the cut edge. Essentially – cutting is precise but due to variation in the printing we need a bit extra to make sure you get a “clean” job. Here is an example of a card that bleeds and the extra image beyond the cut. The red line does not print – it just shows where it cuts. The easiest way to add bleed in Illustrator or InDesign is to use the build in “bleed” setting in the document setup or page setup dialog box.