The dimensions of a "Book of the Dead" could vary widely; the longest is 40 m long while some are as short as 1 m. They are composed of sheets of papyrus joined together, the individual papyri varying in width from 15 cm to 45 cm. The scribes working on "Book of the Dead" papyri took more care over their work than those working on more mundane texts; care was taken to frame the text within margins, and to avoid writing on the joints between sheets. The words "peret em heru", or "coming forth by day" sometimes appear on the reverse of the outer margin, perhaps acting as a label.