A dust cover, book jacket or book cover, protects a book from wear. The dust cover is made from paper with two flaps that fit over the front and back covers, wrapping around the spine to encase the entire cover. It is normally detachable and will increase the longevity and condition of the book.
In addition to protecting a book, a professional dust jacket is also used to promote the book. The cover is typically illustrated and includes title and author. It might also feature a short sentence meant to entice a would-be reader’s interest by capturing the theme or tone of the book.
When buying or selling books their value is greatly enhanced if they still have the dust jacket. This is particularly the case in respect of antiques and specialist editions.