There are two types of polyester velvet.
The first is a cheap, stiff, but very shiny , high pile velvet that looks like real velvet …only not as nice . But it is pretty stain proof , crushes badly, and generally doesn't have to be dry cleaned , unless it's lined .
The second type is stretch velvet. That is often used for skating / dance costumes , and baby clothes, soft dresses and things with a more clingy, stretchy fit. This fabric has a lower , more dense pile is stretchy doesn't crush , and is, and is also washable and stain proof .