A silk does what grid cloth can't: it softens the light while keeping a sense of direction, so faces stay modeled instead of going flat. Poly Silk White is the everyday version of that move, the rag a DP asks for over a window or a key when the light needs to relax but still point somewhere. Sizes run from the 4x4 slip-on up to the 20x20, all sewn in the USA by LA Rag House. It will spend more time out of the bag than in it.