Portrait of a Killer: Jack the Ripper—Case Closed that a paper manufacture expert she hired asserts that reams of paper supposedly used by Jack the Ripper to write several letters to Scotland Yard and paper purchased by Sickert's mother bear the same small-press watermark. She also claims that there are matches in the cutter's marks, which are a result of the rough cutting of each quire (or small package) for packaging. A "quire" was usually of 24 sheets. Though Cornwell's book sold many copies, many Ripperologists and other critics argued that Cornwell's theory was far from persuasive. Critics also note that Cornwell has said that she did not
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