Bibliographic format refers to the proportional relationship between a full sheet of paper and the folded and cut leaves of a book. For example, a text printed two-up so that the sheet of paper needs to be folded once to make the leaves of a book is in "folio" format. A book printed four-up on a sheet that's folded in half, then in half again, is a "quarto" and so on.
Confusingly, many of the same terms were also used as standard paper size names (similar to the way "letter" and "legal" are used as paper sizes in the United States today). Even more confusingly, many of the same terms came to be used as general indications of a book's height, beginning in the 19th century. In the context of book height, "octavo" means "little", "quarto" means "ordinary size", "folio" means "big", and "elephant folio" means "huge"). When someone at the Folger refers to "a folio," you have to rely on context to know if that means an oversize book, a book in in folio format, or one of the first four editions of Shakespeare's collected plays.
Abbreviations and names for formats include:
|DCRM(B)||Gaskell||Ordinary spoken English||Latinate spoken English||Other|
|full-sheet||1⁰||broadsheet, full sheet|
|fol.||2⁰||folio||folio||fo., 1/2⁰, f⁰, F|
|4to||4⁰||quarto||quarto||1/4⁰, Q⁰, Q|
|long 12mo||long 12⁰||long twelvmo||long duodecimo|
|long 24mo||long 24⁰||long twenty-fourmo||long vicesimo-quarto|
NB. for search-and-replace updating:
- character following the number may be:
- degree symbol
- superscript zero
- superscript lower-case letter "o"
- be careful of the order of operations, e.g. change "12⁰" to "12mo" before changing" 2⁰" to"fol." or you'll end up with "1fol."
- Descriptive Cataloging of Rare Materials (Books), the international standard for rare books in library catalogs.
- Philip Gaskell, A New Introduction to Bibliography. Reprinted with corrections in 1995. New Castle, Del.: Oak Knoll Press, 2007