Underdrawing is a preparatory drawing done on a painting ground before paint is applied,[1] for example, an imprimatura or an underpainting. Underdrawing was used extensively by 15th century painters like Jan van Eyck and Rogier van der Weyden. These artists "underdrew" with a brush, using hatching strokes for shading, using water-based black paint, before underpainting and overpainting with oils.[citation needed] Cennino D'Andrea Cennini (14th century most likely) describes a different type of underdrawing, made with graded tones rather than hatching, for egg tempera.