A glossary of bookbinding terms

Twenty short definitions covering the vocabulary that comes up across the journal — signatures, sewing, spines, and hard covers — written for readers who have never picked up an awl.

Signature: A single folded section of a book, usually 8, 16, or 32 pages, sewn as one unit alongside the others that make up the text block.
Kettle Stitch: The linking stitch at the head and tail of the spine that ties each new signature to the one before it during sewing.
Spine: The folded, bound edge of a book where the signatures are joined and, on a hardcover, where the case attaches.
Text Block: The sewn or glued body of pages on its own, before covers, endpapers, or a case are added.
Endpaper: The folded sheet at the front and back of the text block that joins the pages to the case — part pastedown, part free leaf.
Case: The assembled hard cover of a book: two boards and a spine piece, usually covered in cloth, paper, or leather.
Hollow Back: A paper or cloth tube glued to the spine that separates it from the text block, which is why some hardcovers open flat.
Tight Back: A spine glued directly to the text block with no hollow, common on older bindings, which tends to resist opening flat.
Headband: A small woven or stuck-on band at the head and tail of the spine, originally functional and now often decorative.
Super (Mull): An open-weave fabric strip glued across the spine of the sewn text block, adding strength before the case goes on.

Board: The stiff panel, often binder's board or millboard, that forms the front and back cover of a hardbound book.
Joint: The hinge area where the board meets the spine, allowing the cover to open and close without the case cracking.
Foredge: The outer edge of the text block, opposite the spine — the side you fan through to find a page.
Collation: The process of checking that a text block's signatures and pages are complete and in the correct order before sewing.
Sewing Station: A punched hole along the fold of a signature through which thread passes during sewing, placed to line up across the whole text block.
Guard: A narrow strip of paper or fabric used to reinforce a weak signature fold, or to extend a single leaf so it can be sewn in properly.
Pastedown: The half of the endpaper that is glued flat to the inside face of the board, as opposed to the free-hanging half.
Grain Direction: The alignment of fibers in a sheet of paper, which determines whether a fold sits flat or fights back and eventually cracks.
Backing: Shaping the spine into a slightly flared shoulder after sewing, so the boards have a ridge to seat against.
Rebacking: Replacing a damaged or detached spine piece while keeping the original boards, a common repair on an otherwise sound case.