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
Units of paper quantity the good quires ("insides"). These outside quires were known as "cassie quires" (from Fr. "cassée", "broken"), or "cording quires" and had only 20 sheets to the quire. The printer William Caslon in a book published in 1770 mentions both 24- and 25-sheet quires; he also details printer's wastage, and the sorting and recycling of damaged "cassie" quires. An 1826 French manual on typography complained that cording quires (usually containing some salvageable paper) from the Netherlands barely contained a single good sheet. It also became the name for any booklet small enough to be made from a single quire of paper.