quarto

A quarto is a book format created by folding a sheet of paper twice, producing four leaves (eight pages) per sheet. The resulting page size is approximately half the area of the original sheet. In practical terms, if you begin with a standard full sheet, a quarto page typically measures around 9.5 by 7.5 inches, though exact dimensions depend on the parent stock size and the binding method used.

The quarto emerged as a standard during the early days of letterpress printing, when a sheet of printing paper was expensive and wasteful offcuts were a serious concern. By folding systematically, printers maximized yield and created a portable, readable format. The term comes from the Latin quattuor, meaning four, referring to the four leaves produced from each fold. Quarto remained the dominant book size for serious literature, scholarship, and fine printing well into the 20th century.

Production and variants

A true quarto requires two folds perpendicular to each other. The first fold produces a folio (two leaves), and the second fold on that folded sheet produces the quarto. Some printers achieve similar page sizes through different folding patterns, but strict quarto demands this two-fold geometry. The signature, or gathering, created from a single sheet contains four leaves of numbered consecutive pages. When multiple sheets are stacked and folded together before binding, each sheet contributes eight pages to the final book spine.

Quarto was overtaken gradually by octavo (eighth-size) formats as paper became cheaper and readers sought more portable books. However, quarto remains valuable for large-format reference books, art volumes, and heritage printing where page area and readability justify the extra material cost. Modern quarto books are less common than they were four centuries ago, but the format still appears in high-end edition work and specialist printing, particularly where the original quarto layout of a historical text must be preserved for scholarly accuracy.