Painted in 1956, Elliptical Planes captures Karl Benjamin at a pivotal moment in his development as one of the foremost voices in California Hard Edge abstraction. Measuring an expansive 121.9 by 182.9 centimeters, the composition deploys interlocking curved forms across a substantial field, generating a sense of dynamic tension through the precise calibration of color relationships rather than any reliance on illusionistic depth or gestural mark-making. Benjamin's command of pigment is evident in the flatness and clarity of each plane, where adjacencies between hues produce optical vibration that rewards sustained looking. The work situates itself comfortably within the broader constellation of mid-century West Coast modernism, yet it retains a distinctly personal logic. While Benjamin's contemporaries in the loose grouping later associated with Abstract Classicism, including John McLaughlin, Frederick Hammersley, and Lorser Feitelson, shared his commitment to geometric rigor, his elliptical vocabulary sets him apart, introducing a softened dynamism absent from strictly rectilinear compositions. Elliptical Planes demonstrates his ability to balance mathematical discipline with sensory warmth, a quality that has sustained serious critical and collector interest in his work across decades. For collectors focused on postwar American abstraction, this painting represents a historically grounded acquisition from the period widely regarded as Benjamin's most formative. Offered through Louis Stern Fine Arts, the work bears the artist's signature and presents in strong original condition, making it a compelling example of a moment when California was actively rewriting the terms of geometric painting in America.