I'm on the road and can't post pics of the results, but anyone close to an art supply store ought to check out this stuff. It's slow drying (12 hours), but doesn't tend to run or sag like epoxy. You can build it up while wet, too. I've been using it on Poxy Back wing cases and Czech nymphs, but I can see real possibilities for epoxy head streamers and such. Download the pdf color chart to see what I mean.
It dries hard as epoxy and adheres well to anything I've put it on. Comes in a squeeze bottle with a little tiny nozzle, but I'm too clumsy to apply it directly to flies. Instead I squeeze out a little dab and apply with my dubbing needle. Cleans up with water, no less!