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Perfect (Softcover) Binding

The perfect binding process, commonly referred to as softcover binding, results in a book with a glued binding and a squared-off spine.

Smyth Sewing

PrintNinja’s perfect binding process, the collated signatures of the book block are sewn together using the smyth sewing technique. Smyth sewing uses thread to first sew through the folds of each signature and then sew the entire group of signatures (book block) together, resulting in a durable binding that can be opened relatively wide – a great option if you have any pages with continuous spreads.

Traditional perfect binding involves cutting the signatures off at the fold instead of sewing them, resulting in a much less durable binding, with much more content lost in the gutter between pages


Smyth Sewn Signatures Being Glued Softcover Perfect Bound

Next, a tech will place the sewn book block into a clamp that tightly holds the body together while it moves through the binding process. First, glue is applied to the spine and run through a heating process, after which the cover is wrapped around the book block.


Finally, the bound books are trimmed down to size using a special cutting machine that trims all 3 edges in the same process.

Our domestic facility utilizes a perfect binding machine that bypasses the use of folded signatures and instead uses cut sheets that are then ground with a rough edge to ensure excellent glue adhesion. The interior pages are then attached to the covers and a three knife trimmer cuts the books down to their final size.

Watch a short clip of softcover books being trimmed in our international facility

Watch a short clip of softcover books being trimmed in our domestic facility

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