Josef Albers (1888–1976) was a progressive German artist who taught at the Bauhaus, and went on to become one of the most influential art teachers in the United States. He held posts at the influential Black Mountain College in North Carolina, and at Yale University, where he taught color theory and abstraction, and experimented with visual perception and illusion. Albers is known for his series of prints and paintings titled Homage to the Square, in which he placed a square within a square using various colors, creating a dynamic and often ambiguous sense of depth, geometry, and color contrast. For such apparently simple paintings, Albers was able to use the square to experiment with color theory and depth perception in a profound way.