This document is written for Illustrator CS3. Read the Illustrator CS5 print document creation tutorial here.
Any printed work should be in CMYK mode, 300dpi resolution.
Bleed ensures that the design will reach the edge of the paper (“medium”) when printed and cut down to size. A design with bleed is usually set up to be approximately 6mm larger than the final design in both dimensions. This gives 3mm on all sides, which will be removed after printing.
For example, A4 printers cannot print right to the edge of the paper, leaving a white border around the edge. If you want to have print all the way to the edge, you must print the document on larger paper (SRA3 – larger than A3), then cut it down to size. A4 = 210x297mm; A4 with bleed = 216x303mm.
Additionally, all important aspects of the design (text, logos, images) should be kept away from the edge of the document, to avoid them being cut off. A further margin of 5mm should be enough to keep them in the printing “safe zone”.
Create a new illustrator document: for print (CMYK, 300dpi), with bleed (+6mm to each dimension)
Either use View>Guides>Unlock Guides, or ctrl+alt/cmd+;
Click and drag either ruler to create a horizontal or vertical guide. Position four guides, each 3mm from an edge of the document.
This shows the final size of the document after trimming.
…this time a further 5mm in from the previous guides, to form the printing “safe zone”.
Use View>Guides>Lock Guides, or ctrl+alt/cmd+;