Bister: a brownish-yellowish pigment made from the soot of burned wood.

Chiaroscuro: (n) the treatment of light and shade in drawing and painting. An effect of contrasted light and shadow created by light falling unevenly or from a particular direction on something. “The chiaroscuros of cobbled streets.”—OED “[the first movement of Bach’s 2nd Brandenberg Concerto] is like a moving chiaroscuro.”—O’Connell.

Daub: a painting executed without much skill.
Decoupage: the decoration of the surface of an object with paper cut-outs, which is then usu. varnished or lacquered. From the fr. Decouper, “cut out.”
Diptych: 1. A painting, esp. an altarpiece, on two hinged wooden panels that may be closed like a book.

Fresco: a painting done rapidly in watercolor on wet plaster on a wall or ceiling, so that the colors penetrate the plaster and become fixed as it dries. This method of painting, used in Roman times and by the great masters of Italian Rennaisance inc. Giotto, Masaccio, and Michelangelo.
frottage: the technique or process of taking a rubbing from an uneven surface to form the basis of a work of art. A work of art produced in this way. see def.sex.

Indelible: (of ink or a pen) making marks that cannot be removed. (Durant, Oriental)

japanned/japan: a hard, dark, enamellike varnish containing asphalt, used to give a black gloss to metal objects. A kind of varnish in which pigments are ground, typically used to imitate lacquer on wood. Articles made in the Japanese style, esp. when decorated with lacquer or enamellike varnish. (v) cover with a hard, black varnish. (Lawrence)

Pierrot(s): a stock male character in French pantomime, with a sad white-painted face, a loose white costume, and a pointed hat.

Repose: harmonious arrangement of colors and forms, providing a restful visual effect.

Style: an archaic term for ’stylus.’ (Durant, Oriental)

Triptych: a picture or relief carving on three panels, typically hinged together side by side and used as an altarpiece; a set of three associated musical, literary, or artistic works intended to be appreciated together.

Verdigris: a bright bluish-green encrustation or patina formed on copper or brass by atmospheric oxidation, consisting of basic copper carbonate.

Veronal: trademarked name for barbital. Maugham.