Michelangelo Buonarroti, Studies of Male Heads, Helmets for Soldiers and Facial Features, c.1504. Pen and brown ink and black chalk on paper, 20.5 x 25.3 cm. Hamburger Kunsthalle, Kupferstichkabinett. Photo: © Hamburger Kunsthalle / bpk. Photography: Christoph Irrgang