Preliminary drawing made before the application of an overlying layer. Although most commonly understood as the preliminary sketch on a panel, canvas or parchment, the term is also applicable to works on paper that have multiple layers of drawing in different media, such as a black chalk underdrawing for a metalpoint or pen-and-ink sketch. Underdrawings are discussed as a working stage of a finished drawing or painting in early artist's manuals and technical treatises by Cennino Cennini, Karel van Mander, Vasari, Paolo Pino and Albrecht D?rer, among others. Some underdrawings have always been visible to the naked eye, especially in drawings and in thinly painted or unfinished pictures. However, the actual detection and documentation of many only became possible through the use of infra-red techniques, specifically infra-red reflectography (see TECHNICAL EXAMINATION,
See the Abbreviations for further details.
