Bleed is the printed content that should be added beyond the edge of the page to compensate for tolerances in the trimming process. If the artwork on your printed piece goes all the way to the edge of the paper, you need to add bleed so there won't be white edges on the page.
A good rule of thumb is to extend your artwork beyond the trim edge of the page by at least 1/8" (.125"). For example, the artwork supplied for an 8.5" x 11" document that bleeds on all four sides should actually measure 8.75" x 11.25".
If your document doesn't bleed, you can supply your artwork at the trim size. If you are unsure about how to add bleed, please contact a Greenerprinter customer service representative at firstname.lastname@example.org or 1-800-655-5833