'''F4''' is a paper size {{convertcvt|210|x|330|mm|in|2|abbrsigfig=on3}}.<ref>[http://www.prographic.com/Paper_sizes/body_paper_sizes.html Prographic paper sizes] {{webarchive |url=https://web.archive.org/web/20040704181010/http://www.prographic.com/Paper_sizes/body_paper_sizes.html |date=July 4, 2004 }}</ref> Although metric, based on the A4 paper size, and named to suggest that it is part of the official [[ISO 216]] paper sizes, it is only a ''de facto'' standard.
It mayis beoften referred to as "foolscap" or "folio" because of its similarity to the traditional foolscap folio size of {{convertcvt|8+1/2|×x|13+1/2|in|mm|1sigfig=3}}.
