About Evertz's paintings Mattera observes: "while the chromatic stripes are rigorously parallel, the grays are painted at an angle. That is to say that in the thickness of one stripe, two extremely acute angles of slightly different values are painted; what starts out thick at the top tapers to nothing at the bottom, while what starts out thick at the bottom tapers to nothing at the top. It's subtle but potent." Writing about the Hard Edge Painting show Mattera notes: "While the Washington painters worked largely on unprimed canvas, the Los Angeles group worked in oil, and the New Yorkers in acrylic. Medium may not be immediately or even necessarily apparent so much as the result, which is optically compelling both compositionally and chromatically."