Most printers you encounter will require that your projects include a bleed. A bleed of 3mm is usually requested.
The reason that a bleed is necessary is because it creates a margin of error when it comes to cropping the printed product. As an example, imagine you’re making a poster from a photograph. If the paper is trimmed at exactly the right place there will be no problem. However, if there is any variation as to where the paper gets trimmed you will end up with a poster that has edges that haven’t been printed on. Therefore if you include a bleed, a small variation won’t be noticed as the edge of the photograph will have been extended.
Bleed specifications can vary from printer to printer, however it is generally considered advisable to use a bleed of 1/2 inch or more. Publishing software such as Adobe InDesign has built-in bleed settings which makes it easy for you to work with, turn on / off bleeds as well as to be able to export with the proper settings and marks.
About the Author: keir
