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
Paper × 841 mm). A1 is half the size of a sheet of A0 (i.e., 594 mm × 841 mm), such that two sheets of A1 placed side by side are equal to one sheet of A0. A2 is half the size of a sheet of A1, and so forth. Common sizes used in the office and the home are A4 and A3 (A3 is the size of two A4 sheets). The density of paper ranges from for tissue paper to for some speciality paper. Printing paper is about . Paper may be classified into seven categories: Some paper types include: