Charcoal may be one of our oldest drawing materials. There is evidence of charcoal in drawings on cave walls done as many as thirty thousand years ago.
Charcoal is made in a very simple way: when wood is burned quickly it disintegrates and forms soft, grey ash; but if wood burns very slowly, it chars without breaking down, forming charcoal. In the past people used to make charcoal by placing twigs (from willow, vine and plum trees) in earthenware jars and putting these into a low-burning fire for a very long time. Charcoal is still made in a similar way today.
As pressure is applied in different ways, charcoal can make very different kinds of mark: it can be bold, heavy, and dramatic, or it can be light and translucent. It is possible to use the sides or the tip of the stick of charcoal, making broad, fat lines or delicate, fine lines. It is much softer and blacker than pencil, and so can create strong contrasts. Because it is soft, it also crumbles and can easily be blended or rubbed and used to make a range of smudgy marks and tones.
Because it does not have a binder, particles can easily smudge and be wiped away; finished work needs to be handled with great care. Fixative can be sprayed onto a charcoal drawing to stop it smudging.