Printers generally print on larger sheets than the final required size, this is because most printing devices are unable to print to the edge of the sheet, so if the design runs to the edge of the page, part of the design would be lost.
We therefore request that PDF files are supplied with crop marks (also called trim marks) and bleed. Crop marks show where the paper will ultimately be trimmed and bleed is the area outside of the crop marks where the design extends to. The purpose of bleed is to provide some tolerance when printing and guillotining and therefore avoid white lines on the edge of the page. We recommend adding 3mm of bleed wherever possible.
Crops and Bleed explaination (PDF, 127kB)When designing, there is a safe area inside the trim where it isadvisable to not allow text to extend beyond. This should be a minimum of 5mm from the edge of the page.
