cookie
n.— «The effect he explains, though is what we would refer to as “modeling” the light, which involves taking it away in certain spots to create shadows and add mystery. one way to achieve this effect, and what I think he is referring to specifically, is by using a cucoloris, or a “cookie.” a cookie is a frame, usually made of wood that has a pattern of amorphous blobs cut out (sort if like camouflage) that gets rigged in front of a light source creating random pools of light and a lot of shadows.» —“Re: Punishing the light” by Johnny North personal email (New York City) May 4, 2004. (source: Double-Tongued Dictionary)
Further reading
Twice a day the River Thames recedes, revealing a muddy shoreline. Hobbyists known as mudlarks stroll the surface searching for objects that have found their way into the river over the centuries, everything from ancient Roman jewelry to modern...
What if, instead of being an inanimate object, a dictionary were alive? That’s the idea behind a lavishly illustrated new children’s book called The Dictionary Story (Bookshop|Amazon) by Oliver Jeffers and Sam Winston. This is part of a...