The green/red patterns are tied with bi-filar wire we use to build RF transformers. The two wires are bonded together which helps in tying. The down side is it is very stiff. I don't even bother to tie in the wire. Just wrap it on. I have a few others that I lacquered after wrapping. I think we have olive and blue wire as well. Have to hit the stock room when I'm back in on Monday.
I like the UV Knot Sense but it has a very short storage life. After about six months it doesn't harden completely and stays tacky, picking up dirt. I'm also leery of ordering it in winter since it shouldn't be frozen. I'm out right now and probably have to wait to the VF show to pick some up.
Henry, did you get a sample at the last tying night?