The Matthews 48"x48" Cucoloris Cello is used to create shadow patterns on backgrounds or subjects. A flatly lit wall can be broken up into interesting pools of light and shadow. Lighting directors frequently use them to simulate sunlight filtering through trees. While the wood "cookies" create a distinctive pattern, the Cello "cookie" projects a more subtle pattern. The pattern itself depends on the distance of the light source and the distance to the background.