Albers was a professor at the Bauhaus before leaving his native Germany in 1933 for the United States, where he taught at Yale University and Black Mountain College, among other art schools. As a teacher, his influence in this country was enormous and can be detected in the works of a diverse range of artists, including Peter Halley, Donald Judd, and Robert Rauschenberg.

Impossibles (1931) dates from Albers’s years at the Bauhaus and represents his experiments with nontraditional materials and techniques. The mechanical means of producing such glass pieces allowed him to achieve the discipline and detachment that he considered necessary to create nonrepresentational forms. Like other artists of his generation, Albers moved from a figurative style of picture making to geometrically based abstraction. Homage to the Square: Apparition, painted in 1959, is a disarmingly simple work, composed of four superimposed squares of oil color applied with a palette knife directly from the tube onto a white, primed Masonite panel. It is part of a series that Albers began in 1950 and that occupied him for 25 years. The series is defined by an unmitigating adherence to one pictorial formula: the square. The optical effects Albers created—shimmering color contrasts and the illusion of receding and advancing planes—were meant not so much to deceive the eye as to challenge the viewer’s faculties of visual reception. This shift in emphasis from perception willed by the artist to reception engineered by the viewer is the philosophical root of the Homage to the Square series. Albers tried to teach the mechanics of vision and show even the uninformed viewer how to see. He was always proud that many nonart students took his classes at Yale.

The Homage to the Square series is also distinguished by the carefully recorded inscriptions of technical details on the back of each panel. This codification of the making of the painting, along with the reductively systematic application of colors, anticipated much of the art of the mid-1960s, when painting was stripped of the transcendental, and (in the case of Conceptual art) the paint was often left out altogether.