Bleeds are one of the most common file problems that we come across. A bleed is the term for printing that extends to the edge of a sheet. A business card with a printed background is a good example of a bleed.
When designing a printed product that has a bleed (prints to the edge) you need to include a bleed margin that will be cut off after printing. If I drew a 2″ x 3.5″ black box and told you to cut it out without cutting into the black and without leaving white around the box it would be close to impossible. You would be bound to cut too much or too little and you would either end up with a box that was too small or a box that was too big and had white around the edges.
A bleed margin allows the printer to make the cut without having to worry about the dreaded white sliver. At Sac Digital we request an extra 1/8″ on all sides for jobs that have bleeds. This means if you are printing a business card at 2″ x 3.5″ you would submit a file that is 2.25″ x 3.75″ (1/8″ bleed on all sides).
Tutorial on creating a full bleed business card in Adobe Photoshop:
Tutorial on making full bleed business cards in Adobe InDesign: