Keywords: Leonardo da vinci, Comparison of scalp skin and onion.jpg Artwork Creator Leonardo Da Vinci 1489 Pen ink and red chalk on paper size mm 203 152 Institution Royal Library Windsor object history credit line accession number WGA link 12821 http //www wga hu/art/l/leonardo/10anatom/2head2 jpg http //www wga hu/html/l/leonardo/10anatom/2head2 html PD-old-100 graphics study Italian 1451-1500 WGA form graphics WGA type study WGA School Italian WGA time period 1451-1500 Codex Windsor Anatomical studies by Leonardo da Vinci |