[pronounce ke-ar-ros-ku'-ro . A style of painting now called “black and white.”
“Chiar-oscuro ... is the art of representing light in shadow and shadow in light, so that the parts represented in shadow shall still have the clearness and warmth of those in light; and those in light, the depth and softness of those in shadow.” —Chambers: Encyclopædia, iii. p. 171.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894