In his artistic practice Gary Schlingheider deals with the synthesis of painting, sculpture and installation art. He explores linear forms and effects in space, playing with reduction and perception. In doing so, he experiments with a variety of materials and techniques, including canvas, steel, aluminum, acrylic, lacquer, and space itself.

Schlingheider's sculptural works focus less on the conventional haptics of an object and more on its optical and aesthetic appearance as well as its effect on the viewer. In this respect, Schlingheider is influenced by the U.S. "Hard Edge" artist Ellsworth Kelly, whose abstract paintings later gave way to spatial and sculptural forms. Other artistic influences can be found in German Constructivism and the concrete art of the 1960s, as well as in Conceptual Minimalism and its search for objectivity and structured clarity.