As was so often the case with women back in the day, Suzanne Valadon was a muse before she became an artist. A popular model among the painters of Montmartre, she was for two years the lover of Henri de Toulouse-Lautrec. While posing, Valadon watched the painters and their techniques. Eventually, Renoir found her working on a self-portrait. Degas became her main supporter, helping her move from model to artist. Valadon’s subject matter never changed: she painted women, often nude, with a realism both brutal and beautiful. This retrospective looks at all aspects of Valadon’s work—her artistic achievement, her business dealings, her self-marketing. —E.C.