Preliminary drawing that lies under the final painted or inked image.
Preliminary drawing that lies under the final painted or inked image. Prior to the eleventh century, underdrawing was often executed with a hard point, but thereafter a metal point, especially a lead point, or diluted ink was generally used. Styli, dividers, and compasses were sometimes employed in the laying out of a design throughout the Middle Ages. See also backdrawing.
Michelle Brown, Understanding Illuminated Manuscripts (Malibu, CA: J. Paul Getty Museum in association with the British Library, c1994).