what does the word "foolscap" as in a paper sheet come from and what does it describe?

Question

It is a commenly term used for a blank sheet of paper.

Answer 1

You can read all about foolscap at wikipedia witch is where Barbara K got her answer from.

http://en.wikipedia.org/wiki/Foolscap_folio

Answer 2

Foolscap was named after the fool's cap and bells watermark commonly used from the fifteenth century onwards on paper measuring 17 × 13½ inches (432 × 343 mm) or a subdivision of this into halves, quarters and so on. The earliest example of such paper that is firmly dated was made in Germany in 1479.

Answer 3

I think it has Latin roots: fogliocapo or something phonetically close.