Paperback

A paperback (softcover, softback) book is one with a thick paper or paperboard cover, also known as wrappers, and often held together with glue rather than stitches or staples. In contrast, hardback (hardcover) books are bound with cardboard covered with cloth, leather, paper, or plastic.

Inexpensive books bound in paper have existed since at least the 19th century in such forms as pamphlets, yellowbacks and dime novels. Modern paperbacks can be differentiated from one another by size. In the United States, there are "mass-market paperbacks" and larger, more durable "trade paperbacks". In the United Kingdom, there are A-format, B-format, and the largest C-format sizes.

Paperback editions of books are issued when a publisher decides to release a book in a low-cost format. Lower-quality paper, glued (rather than stapled or sewn) bindings, and the lack of a hard cover may contribute to the lower cost of paperbacks. In the early days of modern paperbacks, the 1930s and 1940s, they were sold as a cheaper, less permanent, and more convenient alternative to traditional hardcover books, as the name of the first American paperback publisher, Pocket Books, indicates. In addition, the Pocket Books edition of Wuthering Heights, one of the first ten books it published in 1939, emphasized the impermanence of paperbacks by telling readers: "if you enjoyed it so much you may wish to own it in a more permanent edition", they could return the 25 cent book to Pocket Books with an additional 70 cents and it would send them a copy of the 95 cent Modern Library edition "substantially bound in durable cloth."

Since the mid-20th century, paperbacks can also be the preferred medium when a book is not expected to be a major seller and the publisher wishes to release the book without a large investment. Examples include many novels and newer editions or reprintings of older books.

Because paperbacks tend to have smaller profit margins, many publishers try to balance the profit to be made by selling fewer hardcovers against the potential profit to be made by selling more paperbacks with a smaller profit per unit. First editions of many modern books, especially genre fiction, are issued in paperback. Best-selling books, on the other hand, may maintain sales in hardcover for an extended period to reap the greater profits that the hardcovers provide.^{[citation needed]}

The early 19th century saw numerous improvements in the printing, publishing and book-distribution processes, with the introduction of steam-powered printing presses, pulp mills, automatic type setting, and a network of railways. These innovations enabled the likes of Simms and McIntyre of Belfast, Routledge & Sons (founded in 1836) and Ward & Lock (founded in 1854) to mass-produce cheap uniform yellowback or paperback editions of existing works, and distribute and sell them across the British Isles, principally via the ubiquitous W. H. Smith & Sons newsagent found at most urban British railway stations. These paper bound volumes were offered for sale at a fraction of the historical cost of a book, and were of a smaller format, 110 mm × 178 mm (4+3⁄8 in × 7 in), aimed at the railway traveller. The Routledge's Railway Library series of paperbacks remained in print until 1898, and offered the traveling public 1,277 unique titles.

The Continental market also supported examples of cheap paper-bound books: Bernhard Tauchnitz started the Collection of British and American Authors in 1841. These inexpensive, paperbound editions, a direct precursor to mass-market paperbacks, eventually ran to over 5,000 volumes. Reclam published Shakespeare in this format from October 1857 and went on to pioneer the mass market paperbound Universal-Bibliothek series from 10 November 1867.

The German publisher Albatross Books revised the 20th-century mass-market paperback format in 1931, but the approach of World War II cut the experiment short. Albatross' innovations included a standardized size, use of new sans-serif fonts, use of logo and type on the cover without an illustration, and color-coding the covers by genre.