The octavo format, with eight leaves per gathering, has half the page size of the quarto format before trimming. Smaller formats include the duodecimo (12mo or twelvemo), with twelve leaves per sheet and pages one-third the size of the quarto format, and the sextodecimo (16mo or sixteenmo), with sixteen leaves per sheet, half the size of the octavo format and one quarter the size of the quarto. The vast majority of books were printed in the folio, quarto, octavo or duodecimo formats.[4]: 82