What is bleed
If you are designing a document where any artwork is to go to the very edge of the page, the document will need to be designed on a larger sheet of paper and then cut down to size. The artwork will have to extend into this area of bleed on the extended sheet. Having bleed allows a small amount of space to account for movement of the paper.
A basic rule of thumb is to have 3mm of bleed to every edge of your document. For example if you want your final document size to be trimmed to 210 x 148mm, you will want to design the document at 216 x 152mm. This then gives the printer a comfortable amount of bleed to allow for small movements in the printing.
You will also want to have a ‘safe’ margin area of 3mm inside of your final document size. Again, if you want the final trim to be 210 x 148mm then you will want to keep all crucial design elements inside 204 x 142mm.
Full bleed is the process of printing from one side of the piece of paper / card to the other side. We are able to accommodate full bleed when printing any material, as long as there is sufficient bleed within the document.
In printing, bleed is printing that goes beyond the edge of where the sheet will be trimmed. In other words, the bleed is the area to be trimmed off. The bleed is the part on the side of a document that gives the printer a small amount of space to account for movement of the paper, and design inconsistencies.