A quarto, or 4to, is a type of book or pamphlet that involves folding sheets of paper into four leaves (pages) and cutting them. It is an average-sized format typically employed for creating small books and pamphlets. Moreover, it features four pages per sheet, bound together with staples or string.
“Quarto” derives from the Latin term “quartus,” which means fourth. Occasionally, one might use the word “folio,” which stems from the Latin word for leaf, to refer interchangeably to this specific style. However, a folio usually describes a larger layout.
Inexpensiveness in production has made quartos (4to) highly common for corresponding purposes — albeit their reliability isn’t on par with specific other book formats: accidentally mishandling these prints might lead to damage pretty quickly.
When discussing books, “quarto” refers to the book size rather than the printing format. Books under this size typically measure 9 to 12 inches (23 to 30 cm) in height and can have either portrait or landscape orientation.
In publishing, “quarto” is commonly used as a standard paperback book size reference. However, this term also applies to hardcover books, generally around 10 inches by 13 inches (25.4 cm × 33.0 cm).
Additionally, “quarto” can indicate the size of a paper sheet, which measures about 22.5 inches by 30.5 inches (57.2 cm × 77.5 cm). Once folded in half, a quarto (4to) sheet this size creates four leaves or eight pages.
Quarto (4to) holds great significance within the book and publishing industry as it is a standard size for various publications, including important documents like contracts and legal papers. Many significant manuscripts, such as the Gutenberg Bible, are also preserved in the quarto format.