Complex sentence: In abstract painting during the 1950s and 1960s several new directions like Hard-edge painting exemplified by John McLaughlin expland other forms of Geometric abstraction, as a reaction against the subjectivism of Abstract expressionism began to appear in artist studios and in radical avant-garde circles.
Split into simpler sentences: In abstract painting during the 1950s and 1960s, several new directions, like the Hard-edge painting exemplified by John McLaughlin, emerged. Meanwhile, as a reaction against the subjectivism of Abstract expressionism, other forms of Geometric abstraction began to appear in artist studios and in radical avant-garde circles.