“She has that awful, wonderful itch that defines a real artist,” the British artist Graham Nickson wrote of the painter Mercedes Matter (1913–2001). A close friend of Hans Hofmann, Willem de Kooning, Arshile Gorky, Lee Krasner, and Jackson Pollock, Matter, in 1936, was among the founding members of the American Abstract Artists group, which helped to establish abstraction as a legitimate pursuit in the U.S. In 1964, she founded the New York Studio School. Matter focused on still lifes and figure studies, liberating them from convention by setting her subjects within compressed, fractionated spaces. Resistant to the trappings of a conventional career, she declined a solo exhibition offered by Leo Castelli in the 1950s, insisting she wasn’t ready. Too often overshadowed, Matter is now the subject of an exhibition that traces the arc of her career. —Jeanne Malle