Adds durability to fragile dry flies. Still using my first bottle from 2005 or so. It's held a lot of Elk Hair Caddis together through multiple fish.
Really love this stuff, when I need a head cement to penetrate deep into the wraps. The viscosity is virtually that of water. I often find myself applying this to thread wraps, letting it adequately dry and encapsulate with another UV resin. Bomb proof.