Nick94

Personally I use mucilin floatant, works great, just a small dab to the underside of a fly, reapply whenever. I also use it on my furled leaders, so it's multipurpose in that sense.

I believe I read in some fly tying book (so specific right?) that melting a yarn or mono line with a butane lighter produces a much lighter color than when burning the line with a candle. Never tried, I have only used butane lighters.