books

Today the sizes of books are usually given in inches or centimeters. The American mass market paperback, referred to as “rack size,” is 7 inches by 4⅛ or 4¼ inches, larger than the typical 1950s 6⅜ by 4 316 inches. Trade paperbacks are generally 8 by 5¼ inches.

In the 18th and 19th centuries the sizes of books had names. Most of these names included the size of a signature. A book consists of a number of folded sheets of paper. A printed sheet of paper can be folded in half to make 4 pages; this is a folio. If a sheet is folded in half, and then folded in half again, it will have 8 pages, and so on. The number of pages on a folded sheet is always a power of 2.

One or more folded sheets are nested together to make a signature; in a hard-bound book they are sewn together through the crease. A book's signatures can be seen by viewing the spine from above. In modern printing 32-page signatures are common.

Currently even duodecimo is often pronounced “twelve-mo.”

American

Double Elephant Folio 25"+
Atlas Folio 25"
Elephant Folio 23"+
Folio (F) 13" +
Quarto (4to) 11″–13″
Small Quarto (Sm. 4to) 10"
Octavo (8vo) 8″–9″
Small Octavo (Sm. 8vo) 7½ to 8 inches
Duodecimo (12mo) 7" or slightly more
Sextodecimo (16mo) 6″–7″
Vigesimoquarto (24mo) 5″–6″
Trigesimosecundo (32mo) 4″–5″
Fortyeightmo (48mo) less than 4"
Sixtyfourmo (64mo) about 3"
Miniature less than 3"

British

The old British designations were more precise than the American, and based upon the various paper sizes (see paper) as well as signature size. An abbreviation combines an abbreviation for a paper size with an abbreviation for a signature size. For example, “Dy 4to” is the abbreviation for “demi quarto,” and “Ry Fol” for “royal folio.”

  Octavo (8vo) Quarto (4to) Folio (Fol)
Foolscap (F) 6½ × 4½ 8½ × 6¾ 13½ × 10
Crown (Cr) 7 × 5 10 × 7½ 15 × 10
Large Crown (L Cr) 8 × 5½
Demy (Dy) 8¾ × 5⅝ 11½ × 8¾
Medium (Med) 9½ × 6 12 × 9½
Royal (Ry) 10 × 6½ 12½ × 10 20 × 12½
Imperial (Imp) 11 × 7½ 15 × 11 22 × 15½

home | tools index | search |  contact drawing of envelope |  contributors | 
help | privacy | terms of use