Gesso

Webster's Dictionary of the English Language

·add. ·noun A work of art done in gesso.

II. Gesso ·add. ·noun Plaster of Paris, or gypsum, ·esp. as prepared for use in painting, or in making bas-reliefs and the like; by extension, a plasterlike or pasty material spread upon a surface to fit it for painting or gilding, or a surface so prepared.