Cartoon. The term originated in the Middle Ages and first described a preparatory drawing for a piece of art, such as a painting, fresco, tapestry or stained glass window. In Medieval times the cartoon was drawn directly on the surface of a whitewashed table, which was then used as a pattern for cutting, painting and assembling the window. The cartoon is then divided into a patchwork, providing a template for each small glass piece. The exact position of the lead which holds the glass in place is also noted as it is part of the calculated visual effect.