This portrait is one of a series of sketches Matisse made of his son Pierre's wife Alexina (later married to Marcel Duchamp) throughout 1938. In this drawing we see the artist’s thought process as he redraws a line here, elaborates there, smudges areas for shading, and creates a work at once calculated and informal, seemingly spontaneous. Matisse often used his sketches as preliminary studies for paintings, but in this series they keep their autonomous...