Uni-Yarn comes in some great colors and is a very smooth yarn that makes a great fly tying body material for everything from wet flies to steelhead flies. Uni-Yarn can be used as a body, for wings and for tails. One of the easiest ways to build bodies is to use Uni-Yarn in place of dubbing. Simply wrap it on the hook shank and add a few more wraps towards the front to form a tapered body.