Units of paper quantity the 500-sheet ream has become the de facto international standard. A paper bundle is a quantity of sheets of paper, currently standardized as 1,000 sheets. A bundle consists of 2 reams or 40 quires. As an old UK and US measure, it was previously equal to 960 sheets. When referring to chipboard, there are two standards in the US. In general, a package of approximately 50 pounds of chipboard is called a bundle. Thus, a bundle of 22 point chipboard (0.022" thick) 24" × 38", with each sheet weighing 0.556 pounds, contains 90 sheets. However, chipboard sold in size 11"
Book of Kells sewn together to form gatherings called quires. On occasion, a folio is not part of a bifolio but is instead a single sheet inserted within a quire. The extant folios are gathered into 38 quires. There are between four and twelve folios (two to six bifolios) per quire; the folios are commonly, but not invariably, bound in groups of ten. Some folios are single sheets, as is frequently the case with the important decorated pages. The folios had lines drawn for the text, sometimes on both sides, after the bifolios were folded. Prick marks and guide lines can still be