Bleed is a printing term that is used to describe a document which has images or elements that touch the edge of the page, extending beyond the trim edge and leaving no white margin. When a document hasbleed, it must be printed on a larger sheet of paper and then trimed down.
Bleed Guidelines | What is bleed, how to use bleed, how to add bleed …
How much bleed do you need for printing?
The minimum amount of bleed should be around 0.125” (3mm) outside your document final size, ideally 0.25″ (6mm). Each printer has his own requirement for this. The only time you don’t need to use bleed is when there is absolutely nothing printed on all sides (eg. a design with a white border.)Jul 2, 2015
What does it mean to bleed in printing?
After trimming, the bleed ensures that no unprinted edges occur in the final trimmed document. It is very difficult to print exactly to the edge of a sheet of paper/card, so to achieve this, it is necessary to print a slightly larger area than is needed and then trim the paper/card down to the required finished size.
https://en.wikipedia.org/wiki/Bleed_(printing)
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