(Light Olive Gossamer Silk)
and
(Antique Gold Gossamer Silk)
Mark - Orvis carries this dubbing. Unfortunately the silk dubbing is quite expensive ($3.95/pack). I had a coupon for Orvis, which was burning a whole in my pocket, so I bought all 13 colors.

That hydrophobic comment was what made me think the fly would naturally float if I used this dubbing. It was interesting to find out it would actually absorb the water. Now that I read Mike's comments, I realize that I did not wax my tying thread when dubbing the bodies of these flies. The silk dubbing is very whispy (ultra fine fibers) and it dubs fairly easily without the need for any wax. If I had used a dubbing wax these flies may have resisted absorbing the water and may then float in the surface film.