Commercial printing for businesses throughout the UK & Europe.
Basically, a bleed is artwork that goes over the edge of the printed sheet.
If your design needs to have a bleed then it’s important to allow 3mm overlap (see image A below). As the letterhead will be printed on oversize material (SRA4), this gives the guillotine operator a chance to cut into the artwork and produce a good finished letterhead. (see image B below).
If the artwork ended at the edge of the sheet and the guillotine cut was only 0.5mm out, then we could end up with an unsightly thin white strip down one edge of the sheet, which is not ideal.
Also, if there is a large stack of paper on the press, with the best will in the world there will be the odd sheet that doesn’t get fed through the press 100% accurately so if a bleed hasn’t been put in place this could cause issues.
Extending the artwork over the edge of the sheet allows for a little leeway when it comes to the time for trimming.
If you’ve set your workspace for A4 and intend to use bleeds then, depending on what software package you are using you may need to set the workspace to oversize A4 (SRA4), which measures 225mm x 320mm.