To design a morphology that would become essentially the garment of light, pure geometry was employed: "two planes meeting in space draw a line and nothing else". The object thus becomes little more than a mark on the wall, and light is the undisputed protagonist. Cuma becomes visible and real only when switched on. Despite the initial concept suggesting simpler and more economical technologies, Cuma was die-cast in aluminium to achieve a reassuring thickness and a softness of perimeter lines that would be difficult to attain with other production techniques.