By Garrett Holg, "Ed Alert"
Chicago Sun Times, Sep 28, 1997.

By 1957, Clark was using wide house painter's brushes to paint with boldness and power...

By the early 1960s, Clark was using a pushbroom to literally sweep his paint onto canvases placed on the floor. In "Wasted Landscape" (1961), with its exploding geography, he pushed and spattered broad colliding strokes across the canvas' surface. Here was the vitality he sought.

In a number of newer works, such as "Moroccan Series," Clark has again become more physical. Color, in fact, appears to have been muscled into the paper to create highly expressive and turbulent images.