Ruling

Guide lines which mark the bounds of columns and rows in which text is to be written. Ruling changed gradually after about 1125 from scored lines (created by pressing a sharp object into the membrane) to lead- or plummet-ruled. Ruling grids are a very significant component of manuscript analysis; it is likely that detailed research into the patterns of these grids could provide useful information in our overall ability to assign a manuscript to a particular writing office.