What is FOLIO Format? Introduction & Description
Folio is used as an approximate term for a size of book, typically about 15 in . (38 cm) tall, and as such does not necessarily indicate the actual printing format of the books, which might even be unknown as is the case for many modern books. Other common book formats are quarto and octavo , that are both also printing formats, involving two and three folds in the sheet respectively.
Format A folio (from Latin foliō, abl. associated with folium, leaf [2] ) is a book or pamphlet made up of one or more full sheets of document, on each sheet of which four pages of text are printed, two on each side; each sheet is then folded once to produce two leaves. Each leaf of a folio book thus is one half the size of the original linen. This contrasts with a quarto , folding each sheet twice, and octavo , folding each sheet three times. Unlike the actual folio, these last, and further types involving more folds, require the pages of the book to be cut open following binding, which might be done mechanically by the printer, but in historic books was often left for the reader related to a paper‐knife . Lenox copy of the Gutenberg bible printed in folio format. There are variations in how folios tend to be produced. For example, bibliographers call a book printed as a folio (two leaves per full sheet), but sure in gatherings of 8 leaves each, a "folio in 8s. " The Gutenberg Bible was printed in about 1455 like a folio, in which four pages of text were printed on each sheet of paper, which were then folded once. The actual page size is 12 x 17. 5 inches (307 x 445 mm), a "double folio" size. Several such folded conjugate pairs of leaves were inserted inside each other