This is a good time to double-check alignment and fit. It is also a good idea to check the way the pages backup by putting together a full-sized finished representation or dummy of the piece. Make a set of color separated lasers to compare to your composite lasers. This will help insure that you have not missed an element in the color break or unintentionally used additional colors. Supply your lasers to your printer or service bureau so they have something to refer to when preparing your file for output.
Many people mistakenly believe that lasers are solely for the printer or service bureau.
Printers and service bureaus can print their own if they are not supplied, but differences in systems may cause the files to print differently, thereby giving a false representation of the intended final layout. Printing laser proofs and reviewing them as carefully and thoroughly as you would subsequent proofs will reduce Author's Alteration costs significantly. Another item of particular importance is file management. When making a change to a previously printed piece, always use the most recent file. This will prevent inadvertently missing any changes made in a previous use.