Units of paper quantity as ISO 4046. In Europe, the DIN 6730 standard for Paper and Board includes a definition of 1 ream of A4 80gsm (80 g/m) paper equals 500 sheets. The word 'ream' derives from Old French "reyme", from Spanish "resma", from Arabic "rizmah" "bundle" (of paper), from "rasama", "collect into a bundle". (The Moors brought manufacture of cotton paper to Spain.) Early variant rym (late 15c.) suggests a Dutch influence. (cf. Du. "riem"), probably during the time of Spanish Habsburg control of the Netherlands. The number of sheets in a ream has varied locally over the centuries, often according to the
Toilet paper human history dates back to the 6th century AD, in early medieval China. In 589 AD the scholar-official Yan Zhitui (531–591) wrote about the use of toilet paper: During the later Tang dynasty (618–907 AD), an Arab traveller to China in the year 851 AD remarked: During the early 14th century, it was recorded that in modern-day Zhejiang province alone there was an annual manufacturing of toilet paper amounting to ten million packages of 1,000 to 10,000 sheets of toilet paper each. During the Ming dynasty (1368–1644 AD), it was recorded in 1393 that an annual supply of 720,000 sheets