Re: Ultra Thread Fray
I use UTC 70 denier for almost everything. Given, I use it on the self-retracting bobbins made by Nor-Vise - excess tension will make this stuff come flying apart (and make all sorts of nasty words come flying out of your mouth in the process).
Bobbin tension is a biggie for finer thread. And I agree with Lurky, almost flat is good enough. Given, it's 70 denier thread - which is pretty darn tootin fine - and for doing things like creating a smooth colored underbody, a little twist is hardly going to get noticed, especially by the fish!
(and after excessive amounts of foul language spouting from my own lips while tying jujubee midges with 16/0 Tiemco thread (yes, they do make such a thing) while using, you guessed it, a standard ceramic bobbin, I pulled the trigger and bought extra spools for my Nor-Vise self-retracting bobbin, loaded it up and got the rest of those jujubees done in no time flat. No more popped thread or thread shred.
Everybody has their own idea about how fly tying thread 'shoulld' look and feel. I have used both, and find reasons to use both a multi-strand thread like the UTC thread for losts of things, and a twist thread like Uni or Danville for lots of other things. Not that the two are always interchangeable, but both have their strengths and weaknesses.
More importantly, SET THE HOOK!
I still say he married me because he took me ice fishing and I still wanted to go fishing with him again!