What is bleed and how to use it properly
Bleed is a printing term that refers to printing that goes beyond the edge of the sheet before trimming. 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.
Artwork and background colors can extend into the bleed area. 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, so, to achieve this, it is necessary to print a slightly larger area than is needed and then trim the paper down to the required finished size. Images, background images and fills which are intended to extend to the edge of the page must be extended beyond the trim line to give a bleed.
Bleed in the UK and Europe is generally 3mm from where the cut is to be made.
The example below shows how a full page magazine advert should be set up with bleed. This is the way you must set up your document if you intend to have graphics that extend all the way to the edges of the cut item.
Setting Bleed in InDesign
With InDesign being primarily a desktop publishing application it has the most options for setting up a document for print. Under the New Document menu you will notice individual options for Page Size, Margin and Bleed, simply enter the figures below and let InDesign setup the document for you!
Crop marks are the little lines that sit around the edge of the document showing where the area of bleed ends and the proper document area begins, they work alongside bleed to tell the print worker where the paper needs trimming.
Crop marks are usually hairline or 0.25pt in thickness and are set in registration black. The crop marks will appear on the exported PDF when exported to these Archant magazine settings
Setting Bleed in Photoshop
It is always useful to place in some guides to remind you where the trimmed document size lies, do this by heading to Select > All, then Select > Transform Selection.
Right click on the W and H options and change the measurements to MM, then enter the normal document size.
Drag guides to the borders of the new selection
Don’t forget to add the safe text area, which in this case is 7mm per side. Use the same technique to create guides another 14mm smaller (7mm x 2).
Nb: Adobe Photoshop is not recommended for advert creation, only for image manipulation.