Originally Posted by warbonnetguy
well, if you set your guylines under tension by pulling them really tight, it will act just like a tensioner, and recoil some (not as much as a rubber tubing, but it will recoil), taking up at least some of the slack added by the sagging tarp. this only works because the mason line is so stretchy, and works better with longer sections of line. highly tensioned nylon will remain tight when slack is added (by a sagging tarp for instance), provided the amount of slack added isn't more than the amount of stretch in the line, which is why it won't work well with really short lengths of line.
4' of the stuff has at least a couple inches worth of stretch in it. that will give alot better results than you would get with spectra. i'm not saying it will eliminate the need for tensioners altogether, just make them less necessary like they are with no stretch lines.
I don't know what to say... that hasn't been my experience with nylon guyline. I understand that by putting tension on the tarp and guylines when you initially pitch it you have pre-stretched the tarp such that it will not stretch as far from that point. But that doesn't have anything to do with the guyline selection, that has to do with how you initially pitch the tarp.
You aren't comparing a loosely pitched tarp with sprectra guyline to a tightly pitched tarp with nylon guyline are you?