The folio , is a form of delivers where the printed sheet was folded once, thus giving two layers is four pages. The folio is more or less large, according to the extended of the sheet.

At the 17th century and the 18th century, the folios are generally reference books, extremely bulky (usually approximately 10 kilograms per volume) and have a format close to our current A3 papers (twice larger than the usual page of the office automation printers).

Some famous editions in-quatro

• majority of the editions of the historical and critical Dictionary of Pierre Bayle (1st edition in 1697, 2 folio volumes; edition of 1702, 3 folio volumes)
• the first edition of the Encyclopedia or reasoned Dictionary of sciences, arts and the trades in 35 volumes (17 volumes of texts, 11 of boards, 4 of supplement, 2 of index and 1 supplement of board) of format Folio, was written between 1751 and 1772 on the initiative of Denis Diderot and Jean d' Alembert, Philosophe S of the Century of the lights, on an idea of the bookseller Breton the.

Related articles

• Format of the books
• Printing works