The Gutai Art Association in Japan had a mantra: “Do what has never been done before.” A prominent member of the association until 1968, Ryuji Tanaka believed that art was the material expression of human spiritual freedom. In his work, canvas and paper stained with organic materials—ink, minerals, and other pigments—strikingly juxtapose light and dark to create a powerful, sometimes glittering, presence. “A unification with nature,” said Tanaka, “that is my artistic principle.” —E.C.