Sheet

Any piece of paper may be called a sheet; but for the purposes of the printer, paper is cut up into certain sizes, distinguished by separate names. See Dimensions of Paper. To form leaves, sheets are folded up into sections, which have also their proper names, thus: Folio denotes a sheet of paper folded into two leaves, making four pages; quarto, or, as abbreviated, 4to, is a sheet divided into four leaves, or eight pages; octavo, 8vo, a sheet into eight leaves, or sixteen pages; duodecimo, 12mo, a sheet into twelve leaves, or twenty-four pages. So, also, sixteens, 16mo; eighteens, 18mo; twenty-fours, 24mo; thirty-twos, 32mo; forty-eights, 48mo; sixty-fours, 64mo, are the several definitions of sheets when folded into sixteen, eighteen, twenty-four, thirty-two, forty-eight, and sixty-four leaves; making each twice the number of pages. In presswork, a sheet consists of two formes backing each other. Compositors, in casting-up their matter, charge at so much per sheet.