Before ISO 216 became the international standard, Britain had its own rich tradition of paper sizes.
Foolscap: The Everyday Size
Foolscap (203 × 330 mm) was the standard British writing paper for centuries. Its name comes from the watermark of a jester's cap ("fool's cap").
Quarto, Folio, Octavo
These come from the number of times the sheet is folded:
- Folio — one fold (4 pages)
- Quarto — two folds (8 pages)
- Octavo — three folds (16 pages)
- Duodecimo (12mo) — twelve leaves
- Sextodecimo (16mo) — sixteen leaves
Imperial: The Grand Sizes
- Imperial — 22 × 30 in
- Royal — 20 × 25 in
- Demy — 17.5 × 22.5 in
- Crown — 15 × 20 in
- Elephant — 23 × 28 in
- Double Elephant — 26.75 × 40 in
- Atlas — 26 × 34 in
- Emperor — 48 × 72 in
Why This Matters Today
If you restore a historic book or reproduce an antique print, you need the original size. "Foolscap" and "Imperial" have been in continuous use since the 1600s.