Glossary of Book Repair Terms

Understanding the correct anatomical and conservation terminology makes following book repair instructions much easier. Here is a reference glossary of standard bookbinding terms.

Authoritative reference: Matt T. Roberts and Don Etherington, Bookbinding and the Conservation of Books: A Dictionary of Descriptive Terminology (Library of Congress, 1982).

Acid-free

Materials which do not contain acid and have a pH value of 7.0 or greater (pH neutral or alkaline buffered). Acid-free materials do not cause paper to turn yellow, brittle, or disintegrate over time.

Against the grain

Paper folded or cut at right angles to the primary fiber direction. Well-produced books have the paper grain running head-to-tail (parallel to the spine) so the leaves turn smoothly and lie flat.

Backing

The process of shaping a shoulder or ridge on each side of the text block spine to accommodate the thickness of the cover boards and distribute paper swelling caused by sewing.

Bone folder

A smooth, tapered hand tool traditionally made from cattle bone (or Teflon) used for creasing paper, burnishing mending tissue, smoothing paste, and setting cloth into joints.

Case binding

A method of book construction where the book covers (the case) are manufactured separately from the text block and joined later by gluing down the endpapers.

Crash (Super / Mull)

A coarse, open-weave starched cotton cloth adhered directly to the glued text block spine to line and mechanically reinforce the joints of case-bound books.

Endpapers (Ends / Waste sheets)

The folded sheets placed at the front and back of a book between the protective covers and the text block. The leaf pasted to the inner board is the pastedown; the free leaf is the flyleaf.

Headcap

The folded portion of book cloth or leather that turns over at the head and tail of the book spine, protecting the top of the text block.

Hinging-in

The archival technique of reattaching a loose leaf by pasting a narrow strip of Japanese tissue to the margin of the leaf and adhering the remainder into the gutter of the text block.

Japanese repair tissue

Strong, acid-free handmade paper crafted from long mulberry (kozo), mitsumata, or gampi vegetable fibers. Used in conjunction with starch paste to mend torn paper invisibly.

Kettle stitch

The chain or locking stitch made near the head and tail of each signature that connects adjacent signatures together during hand sewing.

Polyvinyl acetate (PVA)

A flexible, water-based synthetic resin adhesive that dries quickly, remains permanently flexible over decades, does not yellow, and is resistant to microbial growth.

Rebacking

A conservation procedure in which damaged or split cloth or leather on the spine is replaced with a new matching material, while preserving and remounting the original spine piece.

Signature (Gathering / Section)

A group of flat printed sheets folded together in half (usually in multiples of 4, 8, or 16 pages) to form a structural unit sewn through the central fold.

Text block (Book block)

The complete gathering of trimmed, sewn, or glued pages that make up the interior body of a book, excluding the binding case or cover.

Tipping-in

Attaching a loose page into a book by applying a very narrow bead (1/16" to 1/8") of PVA adhesive along its inner margin and sliding it firmly into the spine gutter.

Wheat starch paste

A fully reversible, natural starch adhesive made by cooking purified wheat starch in water. Preferred by archival conservators because it can be safely removed with water without harming paper fibers.