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Folding Signatures

This article will teach you about folding signatures and how they are involved in the offset printing process.

Once the printing is complete, the stacks of fully-printed and dried parent sheets are taken to be folded by the folding machine. Each parent sheet zooms through the machine one at a time entering into gates that are set to the proper fold size. A final fold is applied by a heavy arm – this is called the knife fold – which applies immense pressure on the fold line. The final project rolls out of the machine as a “signature.” The majority of projects are folded by these machines, although extremely large projects or those with unique requirements may occasionally be required to be folded by hand.

Watch parent sheets fly through a folding machine and finish as a signature:


The folded groups of pages that emerge from the folding machine are called signatures. Most projects have signatures of 16 pages (8 pages on each side of the parent sheet), but projects 6″ x 9″ or smaller may have signatures of 32 pages, and projects larger than 9″ x 12″ may only have 8 pages per signature.

Parent Sheets Folded into Signature Machine

Domestic Orders (Digital Offset)

Our Digital offset press produces sheet sizes that don’t require signatures. Instead, these prints are designed to work with specific finishing equipment. These machines will work with a cut edge sheet to produce a perfect bound project, or collated and folded sheets to produce saddle stitched projects. 

See a video of the binding process for perfect bound books at our domestic facility:

See a video of the binding process for saddle stitch books at our domestic facility:

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