WHAT IS BLEED?
Bleed is a printing term that refers to a design that has ink printed all the way to the edge of the finished page.
In order to properly print a design that bleeds, the image in the graphic file must extend past the edge of the paper. The image is then printed on an oversized sheet of paper, and after printing the page is trimmed down to the proper size. Traditionally, the amount of bleed added to an image should be 1/8" (.125") on each edge that bleeds.
As an example, an 8½" x 11" brochure with a full bleed (a bleed on all 4 sides) should have the design extend 1/8" of an inch (.125") past each edge of the page, for a total image area of 8¾" x 11¼" (8.75"x 11.25").
Making bleed for solid color is easy, just extend the edge of the color box 1/8" past the edge of the page. For graphics or photographs, one must be sure there is enough content to extend the image past the edge of the page sufficiently and allow for a bit of flexibility in the position of the final trim cut.
Additionally, any type, graphics, or borders that aren't to be trimmed (non-bleeding) should remain 1/8" inside the edge of the page to allow for flexibility in trimming the page