Paper Cover

A paperback book is, as the name implies, bound in a paper cover rather than anything else more structured. The cover is trimmed to be the same size as the book block so that the cover and pages are the same length, unlike a hardcover book where the cover is bigger to protect that pages.

"Paperback books are bound in paper rather than a case made of boards. The paperback cover is one piece of heavy paper, scored to turn at the spine, and trimmed along with the book block, making the cover and the pages exactly the same size. The book block is (usually) pasted directly into the spine, so it doesn’t separate from the body of the book when you open it. If a book is bound tightly, the spine will need to be 'cracked' so it can open fully."