The Wikipedia defines a sketch as “a rapidly executed freehand drawing that is not usually intended as a finished work. A sketch may serve a number of purposes: it might record something that the artist sees, it might record or develop an idea for later use or it might be used as a quick way of graphically demonstrating an image, idea or principle.” The term is most often applied to graphic work executed in a dry medium such as silverpoint, graphite, pencil, charcoal, or pastel.