In printing and prepress, bleed or bleed allowance refers to the area that is still printed, but which lies outside the actual print and is cut off at the end. The bleed ensures that your printed image has the desired size and shape and that all important elements are visible.
Trimming is important because paper is a medium that is never exactly 100% identical in the printing press, and these fluctuations are amplified in every processing step such as folding and stitching. If the data were delivered in the ‘naked’ final format alone, there would often be a white border at the edge – sometimes at the top, sometimes at the bottom, sometimes on the right, sometimes on the left – caused by the offset of the printed image during printing and further processing.
Most print shops can cope well with a 3mm bleed, Flyeralarm also manages with a reasonable one millimetre, sometimes the bleed specifications are in between or – as for large displays and mega posters – considerably higher, as fabric or tarpaulin distorts even more easily.
If auxiliary marks are placed on the PDF or the print data in InDesign or other layout software or in imposition software, there are also bleed marks that indicate the inner area to which the bleed is to be trimmed and the outer area to which the maximum bleed extends.
Here are some tips for using the bleed:
- Place your print image within the bleed.
- Do not use any elements outside the bleed, e.g. text or graphics.
- Do not place important elements at the edge of the print image.
- Specify the bleed when submitting your print data.
- Set bleed marks so that the bleed is directly visible to the viewer in the PDF.