An Italian term that refers to the contrasts of light and dark in a painting. This means that the forms are not defined by contouring lines but rather by the juxtaposition of light and dark areas. Caravaggio was one of the masters best known for his bold use of chiaroscuro. He lit his figures from a single, usually hidden, source to create theatrical effects that enhanced the drama of his scenes—his purpose to appeal to the senses or to solicit religious devotion from the faithful. In his Calling of St. Matthew (1599-1600) in the Contarelli Chapel at San Luigi dei Francesi, Rome, for instance, he set his figures against a dark background, lighting only the main protagonists in strategic places to call attention to the significance of the moment when Christ invites the saint to join him.
Historical dictionary of Renaissance art. Lilian H. Zirpolo. 2008.