As the 1960s progressed, Pepper turned to using polished stainless steel. In some of the first works, she used a torch to carve used one-inch thick elements of stainless steel. From there, her pieces evolved into highly polished stainless with painted interiors. They are illusionary works that disappear and reappear, mirroring the surrounding landscape. In an interview with the art historian, Barbara Rose, Pepper said "Another effect I'm trying to obtain with this bright finish is not simply illusion, but the inclusion of the person looking at it, so that there's a constant exchange going on between the viewer and the work...My aim here is to invest space with a solidity by filling it with the world around it."