They have several sizes ... (Diamater) the smalller works the best ... They have .. at times .. "Brisele" (SP)Nylon which is straight and stiffer that is used in Saltwater.
Hope that helps .. they have been around since the late 60's or early 70's.
I know a guy that uses a 3/4-1oz. jig with fish hair on it. Uses it about 6" long with some flash. Does great for Striper in saltwater. Myself, I have never used it.
I've tried it.Don't care for it at all.I've got your jigs ready to go,I'll throw some black and white that I've had laying around for years and let you check it out.First I have to find where I put it,lol.
I have some (red) that was given to me and use it only for putting a accent color into thread neck bucktail jigs. It is stiffer/thicker than bucktail for sure.