FishHawk Metallics are the finest metallic threads in the world. This thread is based on a nylon core for maximum strength and windability, with a layer of rice paper added for ultimate flexibility and bonding. The metalizing is silver alloy (not aluminum) so it won't tarnish or lose its luster and shine. Finally it's finished with a polyester film which keeps it smooth, supple and fray resistant. If you have ever struggled with metallic threads that twist up on you while wrapping or when being stored, then you will be pleasantly surprised by how easy to work with FishHawk Metallic thread is. The colors are fantastic and given the relatively small runs of production the quality of both color and function are unmatched.