The Italian word for smoky, it refers to a shading technique developed by Leonardo da Vinci to soften the contours in his paintings and add an ethereal effect. The technique entails gradually darkening colors and layering them onto the pictorial surface in such a way as to blur the lines from light to medium to dark until they become imperceptible. Leonardo's Mona Lisa (1503; Paris, Louvre) and Madonna of the Rocks (1483-1486; Paris, Louvre) embody this technique. In both paintings, the forms seem to be emerging from the dark, a feature that imbues the scenes with an aura of mystery. A number of Renaissance masters adopted sfumato as part of their own visual vocabulary, among them Domenico Beccafumi, Correggio, Giorgione, and Parmigianino.
Historical dictionary of Renaissance art. Lilian H. Zirpolo. 2008.