Kenneth Spencer Research Library

When guests come on a tour of the conservation lab, they are sometimes surprised that book pages are usually held together with thread. (Since many modern paperbacks are glued, not sewn, younger guests are often less familiar with sewn bindings.) There are many sewing techniques, useful in different situations.

Traditionally books were sewn on a piece of equipment called a sewing frame. The frame holds the sewing supports taut so the binder can keep her hands free for the actual sewing. Sewing supports are usually either a broad, flat tape (made of cotton, linen, ramie, leather, or vellum), or a cord (usually linen), around which the sewing thread progresses. Cords make raised bands on the final, covered spine, whereas tapes can be flat to the spine.

A sewing frame set up with three sewing supports of linen tape.

In this example, the book is being sewn with what is known as a supported link stitch, in which each row of stitching is linked to the one before. The center of each folded section of paper is pierced with a sewing needle at a sewing station. At the head and tail of the book are two more stations, called kettles. The kettle stitch is a half-knot or chain, and serves to cinch the newest section of paper to the previous ones.

Left: Supported link stitch with curved needle.
Right: The finished sewing. Note the kettle stitches at each end of the book.

Once the book is sewn it is often rounded and backed, to create a rounded shape on the spine and shoulders for book boards to be set into. Rounding and backing is often done with a special bookbinding tool called a backing hammer in a cast iron contraption called a job backer.

Left: The job backer and backing hammer.
Right: Detail of the rounded and backed book in the job backer.

Whitney Baker
Head, Conservation Services