Fly Rite's Fly-Tite Head Cement is an innovative non toxic cement that is made of all natural ingredients. It dries clear and flexible. 2 fluid ounces comes in this little bottle. I have just started using this product that was recommended to me. And after a few uses, I have to say it is quite easy to work with. No toxic fumes to be concerned with. Gives off a semi-gloss coat. Strengthens your whip finish or adds a nice coat of durability to your flies. You can put down a small layer of the cement on the shank before you begin twisting the thread for durability as well. The stuff is available for $4.95 at Performance Flies.