>Tauntline is what I currently use. Sometimes is loosens on its own do to thin cord. I am sure thicker will not do this.
Ah, but we're about light, here, right?
What is a tautline but a clove hitch (with an extra loop) tied around the load-bearing line? If you have small-diameter or synthetic cord, it won't hold as well as in 1/2" manila. So make another clove-hitch around the load-bearing line. And another if need be. Until you get the friction you want.
