Recto: a drawing in red chalk of the head and shoulders of a bald man turned in profile to the right, traced from the verso. Mathematical calculations, and (the other way of paper) four lines of script. Verso: the same head, and facing it a small grotesque head, in profile to the right.

The disdainful expression of the main figure on the verso is deflated by the rapidly sketched grotesque profile that gazes up at him from heavy-lidded bulging eyes. While it is doubtful if Leonardo rationalised his impulse to sketch such inconsequential profiles, an opposition of types may here have been intended to some degree - aquiline against snub nose, hideously long upper lip against tightly compact mouth - but this is not fully cogitated and cannot have been the main reason for drawing either figure. The addition of the grotesque was the work of no more than a few seconds, a simple visual joke that may have been an impromptu satire on double portraits of couples in facing profile.

A note on the recto reads 'When you make a figure, think well about what it is and what you want it to do, and see that the work is in keeping with the figure's aim and character.' This has been taken as support for the idea that the main figure is a study of a semitic type for the Apostles (and especially Judas) in the Last Supper. It does not however have the character of a preparatory study for a painting, and is likely to be no more than a typical exercise in Leonardo's mature type, severe in aspect, bald and with an odd forward-swept beard. The head on the recto was apparently traced through (in red chalk) from the pen study on the verso, and while doubts have been cast on the authorship of the red-chalk tracing it seems to be a example of Leonardo's tentative early efforts with the medium.

Text adapted from M. Clayton, Leonardo da Vinci: The Divine and the Grotesque, London 2002