1) In the late 1950s, Clement Greenberg began championing a new style of painting he called Post Painterly Abstraction, which moved beyond Abstract Expressionism towards a more purified abstraction.
2) Artists like Helen Frankenthaler, Morris Louis, and Kenneth Noland began using staining techniques that eliminated gestures and focused on the properties of color, creating diaphanous, optically focused works.
3) Josef Albers and Ad Reinhardt also paralleled this trend with their explorations of color theory and attempts to define art as existing purely for its own visual properties rather than expression.