sinopia

With sinopia—the preliminary sketch found on a layer of its own on the wall underneath the fresco, or painting on freshly spread, moist plaster—one reaches the point at which a work that merely served as technical preparation becomes a formal drawing expressing an artistic intention.

Sinopia, the preliminary sketch for a monumental wall painting, was done with the brush and has all the characteristics of a preparatory, form-probing drawing. The sketch was carried out directly on the appropriate spot and covered over with a thin layer of plaster, on which…