n. 用明暗对照所作的素描, 明暗对照法

[ noun ]
a monochrome picture made by using several different shades of the same color
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Chiaroscuro \Chia`ro*scu"ro\, ||Chiaro-oscuro
\Chi*a"ro-os*cu"ro\, n. [It., clear dark.]
(a) The arrangement of light and dark parts in a work of art,
such as a drawing or painting, whether in monochrome or
in color.
(b) The art or practice of so arranging the light and dark
parts as to produce a harmonious effect. Cf.
{Clair-obscur}.