I use EP fibers, but I had heard that Congo hair was the same and much cheaper. A hank of EP fibers will probably last ten years of tying. It floats nice for the sparse hackled low profile flies and takes floatant really well without matting down. It also makes a sturdy post for parachute flies and I also like it for the wing on really small comparaduns, where you will appreciate its floating quality. It also makes a nice semi sparkly body when wrapped as a yarn. I also mix it in with the wing of dark haired elk hair caddis, to give me a little more visibility without being too obvious.