The critic and curator Philip Rawson, an eloquent guide to the means and methods of drawing over the ages, points out that until the Italian Quattrocento, no European sculptor was supposed to be able to draw. In the medieval period, only those sculptors who also worked in two dimensions drew habitually; any other sculptor who needed, say, to show a client a proposed design hired a draftsman to make one. And when sculptors began to make drawings (for their own use or to guide assistants), they tended to do so without thinking of the format of the paper as a frame to which the image should …