The goal was to get the ideal hole size and density. When the light is in front you just see the crinkly gray surface, but when the light is behind you see all the holes light up like little stars. You don't see the surface anymore just the holes and the dark contrast of the opaque. It is aluminum foil crinkled glued onto acrylic sheets. Then it was painted with white acrylic paint mixed with ink, and sanded to create the holes.