Toward the end of 1912, Léger made among the most defiantly abstract works yet seen. Over the next two years he worked intensely in this experimental idiom, producing the fifty or so canvases, and twice as many works on paper, that constitute his Contrastes de formes (Contrasts of forms) series. An inventory of repeated forms—geometric cones, cubes, cylinders—jostle and pile across the surfaces of these works. Here, Léger rejects illusion to focus on the mechanics of representation, drawing attention to them with roughly blocked forms, exposed supports, unmodulated color straight from the tube applied in painterly patches, and highlights detached from any light source. Chiaroscuro, the traditional technique of light and shadow used to create the illusion of three-dimensionality within the two-dimensional reality of the picture plane, becomes a language of absolute contrasts: strident black and white or colored striations clash with one another across the works.
from Inventing Abstraction, 1910–1925, December 23, 2012–April 15, 2013