In-folio or infolio (from Latin in folio, in sheet) or, abbreviated as in-2º, is a technical term used in bookbinding that indicates the size of a book, where the printed sheet has been folded only once on the smaller side, so it gives rise to two folios that are equivalent to four pages.
When the sheet is folded in four, it is called in-fourth or in-4th; if in 8, in-eighth or in-8th; if in 16, in-sixteenth or in-sixteenth; if in 32, in-32º and if in 64, in-64º. History
The folio will be more or less large depending on the sheet of paper. Especially during the period of manual printing, sheets of paper were manufactured in many different sizes depending on the country, workshop or date, so the size of page height can vary between 30.49 and 38, 1 cm. During the seventeenth and eighteenth centuries, the folios are generally books, bulky (they could weigh about 10 kg per volume) and with a paper format close to the A3 standard. Due to its high cost of production, the print run was generally limited to a small number of copies. The filigree used to be located in the center of the page.
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