Kasak began his artistic education in Warsaw, which he later continued in Vienna and Rome, before settling in New York. He practiced a figurative style of painting until the mid-1940s, when he began considering that art should have a more original and universal character, and should break free of the traditional rectangular frame. He also rejected the distinction between painting and sculpture in modern art, and considered negative and positive space equally relevant to the structure of an artwork. Kasak envisioned art as autonomous, as opposed to imitative of reality. He adopted geometric abstraction, and produced three-dimensional constructions. His beliefs and style aligned him with the spirit of international avant-garde groups, and in particular the Argentinean Madí group, of which he became a long-distance member in 1950.