The first definition in Google for Angel Hair says, "Angel hair is an alleged substance of unknown origin, said to be dispersed from UFOs as they fly overhead. It is so named for its similarity to fine hair, or spiders' webs, and is comparable to ectoplasm and pixie dust."
However, the material on this page is composed of strands of very fine Mylar much like Flashabou, but even finer still. Angel Hair is in 6" to 8" strands for tying hot patterns like Scandinavian Tube Flies. It blends well with most other materials including marabou, arctic fox, buck tail, super hair, or winging material. When chopped into shorter strands, it blends with most other furs and synthetic dubbing. Excellent for use in both small and large flies.