bm,

I think it might be what you're looking for. I caught about 40 fish today on the same knot.It's made from "Spectra", a MilSpec textile from the good people at Honeywell. They call it a microfilament, but it looks like a twisted yarn that's been heat-set. I used to work on machines that made kevlar gloves and it's real similar to that type of yarn. Clippers won't cut it.

I got mine at Wal-Mart; here's the website:

http://www.powerpro.com/index.asp