CHIAROSCURO. - It is determined in the vision of objects by the contrast between lighted parts and shadowed parts. In art, it is said that these are reproduced in *chiaroscuro* when their plastic values are rendered with the various gradations of a single tint. In general, this system underlies drawings and engravings; but all pictorial techniques, using a single color, can serve to execute *chiaroscuro* or "monochromes."
*Chiaroscuro* is also an essential part of polychrome painting, which would fail to render relief if it did not reproduce the variations that colors undergo according to whether they are more or less illuminated. In some periods, painters have expressed themselves using pure color, without volumes acquiring definite plasticity through *chiaroscuro*; this is the tendency characteristic of classical art prior to the 5th century and found among the Byzantines, Persians, Indians, and generally among the peoples of the Far East. Classical art after the 5th century, and in general all Western art, do not, however, renounce the plasticity of bodies obtained with the aid of *chiaroscuro*, even when tackling the problem of color.
To the concept of a painting based on chiaroscural values, where lighted parts tend toward white and shadowed parts toward black, there is opposed that of tonal painting, i.e., painting that, following the example of the great Venetians and with notable contributions from modern currents such as the Impressionists, Macchiaioli, etc., bases representation on "tone" harmonies. "Tone" is the value that individual colors acquire according to the quantity of light they absorb and thus reflect.