Kevlar has a habit of cutting itself when tied - I don't recommend
it. There are three products that may work for you.
1) SoftTouch in a 0.010 thickness is the finest of the flexible
stringing wires and will be the most cut-resistant of the three
products I'll recommend.
2) PowerPro is a fishing product. Your local bead store will have a
white version available, otherwise it will be green or a vivid
flourescent yellow (icky). Get the 10 pound test weight - it works
well with seed beads for multiple passes.
3) FireLine, another fishing product. FireLine is a smoky grey color
or a "crystal" translucent pale white color. It won't drape quite as
easily as the PowerPro but it is thinner (get either the 6 pound fine
or the 4 pound extra fine weights for small bead work) and it will
easily thread through a #12 beading needle. The Power Pro will only
thread through a #10 needle fairly easily.
Feel free to Email me off list if you have additional questions and
good luck with the project.
BBR - Sandi Graves, Beadin' Up A Storm
Stormcloud Trading Co
St Paul, Minnesota (USA)