1911 Encyclopædia Britannica/Foolscap
FOOLSCAP, the cap, usually of conical shape, with a cockscomb running up the centre of the back, and with bells attached, worn by jesters and fools (see Fool); also a conical cap worn by dunces. The name is given to a size of writing or printing paper, varying in size from 12 × 15 in. to 17 × 131 in. (see Paper). The name is derived from the use of a “fool’s cap” as a watermark. A German example of the watermark dating from 1479 was exhibited in the Caxton Exhibition (1877). The New English Dictionary finds no trustworthy evidence for the introduction of the watermark by a German, Sir John Spielmann, at his paper-mill at Dartford in 1580, and states that there is no truth in the familiar story that the Rump Parliament substituted a fool’s cap for the royal arms as a watermark on the paper used for the journals of parliament.