Case or edition binding, the most common type of binding for hardcover books, involves sewing the individual signatures together, flattening the spine, applying endsheets and a strip of cloth to the spine. (The book “signatures” are printed sections of the book. The number of signatures varies based upon the number of pages in the book.) The hard covers are then attached. The spine of a case bound hard cover book is typically rounded and there are hinges (grooves) along the edges of the cover near the spine. Case bound books often also have dust covers or jackets.