Die cutting is also applied to the mailer during the collating of it and is part of the construction process. The area between one insert and the next on the roll is die cut out and discarded. 

It is necessary to die cut the area between inserts out so that the insert does not interfere with the cross web gluing and so that the insert will fit within the mailer. The area that is die cut and removed is called the chip. The end cut of the chip can be produced as a slit on the press or it can be produced on the collator. When there are several inserts in the mailer, they are run through together so the die cutting is completed on all of them at the same time.