Heinz Mack is a German artist known as the co-founder of the ZERO movement who worked with light as his primary medium. “For me, light is immaterial,” he explained. “In my case, I prefer to make works that are instruments for light. My sculptures do have a kind of function: of making light visible.” A painter and sculptor, Mack is known for his investigations into luminescence, space, movement, and color, rendered through an array of materials. (Artnet)