Charcoal is a black drawing material made of carbon, commonly used for sketching, under-drawing in paintings, and creating finished drawings.
Charcoal is typically created by heating thin willow twigs without oxygen, resulting in black, crumbly sticks. When applied to paper or fabric, it leaves a line that's denser at the pressure point and softer at the edges.
This makes charcoal suitable for more expressive and freeform studies, although it smudges easily and is often preserved with a fixative spray. In the twentieth century, a refined form known as compressed charcoal was developed.