Hi guys, I've been playing around with some 2:1 Raychem heatshrink that I have an unlimited amount of

, and I was wondering what you guys use under the tubing to get a better grip. It looks like some guys are wrapping wire underneath for a spiral grip.. what gauge of wire works best?
Any ideas are appreciated, and this will be a handy thread for anyone getting sweeper bristles from me because I'll be packing every envelope with these 1" pieces of Raychem 1/8 2:1.

.....Specialization is for insects.
-Robert A. Heinlein