Quarto is the format of a book or pamphlet produced from full sheets printed with eight pages of text, four to a side, then folded twice to produce four leaves. The leaves are then trimmed along the folds to produce eight book pages. Each printed page presents as one-fourth size of the full sheet.
Title page of the first quarto edition of Shakespeare's Midsummer Night's Dream, 1600, from the Folger Shakespeare Library
The size of a book is generally measured by the height against the width of a leaf, or sometimes the height and width of its cover. A series of terms is commonly used by libraries and publishers for the general sizes of modern books, ranging from folio, to quarto (smaller) and octavo. Historically, these terms referred to the format of the book, a technical term used by printers and bibliographers to indicate the size of a leaf in terms of the size of the original sheet. For example, a quarto historically was a book printed on sheets of paper folded in half twice, with the first fold at right angles to the second, to produce 4 leaves, each leaf one fourth the size of the original sheet printed – note that a leaf refers to the single piece of paper, whereas a page is one side of a leaf. Because the actual format of many modern books cannot be determined from examination of the books, bibliographers may not use these terms in scholarly descriptions.
The supposed largest book in the world, as of 1909. It was the visitors' register for the California Building at the Alaska–Yukon–Pacific Exposition in Seattle. Some normal-sized books are on the table at right.
