Ad Reinhart

Photo: John Loengard/Time & Life Pictures, via Getty Images
Reinhardt working on one of his “black” paintings in July 1966.
NYTimes:

From his notebooks and letters, we know how Reinhardt siphoned off most of the oil from his oil paint to achieve a powdery surface. We also know that he added small quantities of color to his blacks in order to differentiate them. And we know how he applied his paint with carefully layered strokes to create the illusion of an unstroked surface. The black paintings are delicate: the mere touch of a finger leaves a permanent imprint. Their fragility contributed to them being perceived, and valued, as pure things in a corrupted world.