Charcoal is one of the first tools humans used to make artwork, appearing in cave paintings dating back 28,000 years. Artists have refined the medium from burnt wood to finely-ground charcoal bound with wax or gum into sticks, crayons, and pencils. During the Renaissance, charcoal was often used to create gestural sketches to prepare for a painting, but charcoal’s range of expression makes it a beautiful medium for finished work, from the gentle ochre used in Da Vinci’s Study of a Woman’s Hands to the intense black of Redon’s spiders.