A type of fabric that is commonly used for drapery, this fabric has the distinctive quality of blocking light, and comes in two forms: 2-pass and 3-pass. Two-pass has two “passes” of foam on a fabric, which means the black layer of foam will be visible. 3-pass has two layers of white and one layer of black foam. Three-pass can also be used as an upholstery fabric, as the black layer is not visible. Blackout fabrics can also be insulating and noise-dampening.