Satin refers to the Weaving of a fabric rather than the material. It typically has a glossy surface and a dull back, one of three fundamental types of textile weaves along with plain weave and twill. The satin weave is characterized by four or more fill or weft yarns floating over a warp yarn, four warp yarns floating over a single weft yarn. Floats are missed interfacings, for example where the warp yarn lies on top of the weft in a warp-faced satin. These floats explain the high luster and even sheen, as unlike in other weaves, the light reflecting is not scattered as much by the fibres. Satin is usually a warp-faced weaving technique in which warp yarns are "floated" over weft yarns, although there are also weft-faced satins. If a fabric is formed with a satin weave using filament fibres such as silk, polyester or nylon, the corresponding fabric is termed a "satin", although some definitions insist that the fabric be made from silk. If the yarns used are short-staple yarns such as cotton, the fabric formed is considered a sateen.