‘Don’t judge a book by its cover’ is an oft quoted and sometimes prudent adage. In the world of rare books, however, a cover can change everything. Here, we ask ‘how do you judge a book by its cover?’ and will be looking at the significance of dust jacket design, the work of binderies, and the place of the private press movement in the history of book production, as well as giving an insight into what booksellers look for in a rare book or first edition.