This self-portrait by Leonardo da Vinci may *look* like it's etched in a coffee stain, but in fact it was drawn by the master with red chalk. It was created by Leonardo sometime around the years 1510-1515. The artist would have been roughly 58 years old in 1510.
The portrait is done in red chalk on paper, and now resides in the Biblioteca Reale, Turin, Italy. Some scholars dispute the notion that the work is a self-portrait, saying that it may be a drawing of another man -- or that the drawing itself may be a fake or a copy. However, over time it has been widely accepted as a self-portrait by the great man himself.