Klee constantly experimented with artistic techniques and the expressive power of color, in the process often breaking traditional or "academic" rules of painting in oils on canvas. Klee also applied paint in unusual ways, such as spraying and stamping during his years at the Bauhaus. Keeping his work within the realm of the "ordinary," Klee also painted on a variety of everyday materials, such as burlap, cardboard panel, and muslin.