 Fontana often lined the reverse of his canvases with black gauze so that the darkness would shimmer behind the open cuts and create a mysterious sense of illusion and depth.He then created an elaborate neon ceiling called "Luce spaziale" in 1951 for the Triennale in Milan.In his important series of "Concetto spaziale, La Fine di Dio" (1963–64), Fontana uses the egg shape.