modocdan
Here in the archives of FAOL is a dandy summary of thread basics. (?)
Chris Helm said in a workshop I attended a few years ago said do not pay any attention to the designations 8/0 and 6/0 and 3/0 when comparing threads across brands; there is no standard. He rather would have preferred dernier as a more realistic indicator of comparable strength. Sounds like you have some rather weak 3/0 material. Try UNI.

Kevlar = strong = $$ = stiff =floats. That's about all I know. Great stuff fordeer hair.

I use Pearsall's for my softhackles 'cause it looks nice and gosamer for rod wrapping for the same reason.

Mark