Maas's law

In papyrology, Maas's law - named after classical scholar Paul Maas (1880–1964) - refers to the observation that columns in bookrolls often exhibit a forward tilt such that both edges of a column gradually move to the left as the column progresses. In other words, the bottommost line of the column of text is further to the left than the uppermost line. William Johnson has argued that this tilt was deliberate and formed part of the bookroll's design.