Charcoal sticks are made by taking twigs from willow or vine and baking them at high temperatures in an airtight container. They are primitive tools for drawing, and while I’m frustratingly far from mastering the technique, I still find charcoal drawing quite intriguing.
Should you feel like making your own charcoal sticks, you could follow the instructions given by Italian painter and handbook author Cennino d'Andrea Cennini (ca. 1360 – ca. 1425) from his Il Libro dell’Arte. I particularly like the part where he writes you should “go to the baker’s in the evening, after he has stopped work…”:
Bibliography
Cennini, Cennino, and Daniel V. Thompson. The Craftsman’s handbook. New York: Dover, 1933.
Finlay, Victoria. Color: A Natural History of the Palette. New York: Random House, 2004.