i've never hung with paracord...i alwaya thought it would be to sretchy/not durable enough
The "real" paracord was made with a braided outer shell and several twisted inner cords. This had a rated breaking strength of several hundred pounds, and usually said so on the label.
A cheaper and lighter paracord is now more common on the market. It had a braided outer shell and no or few twisted inner cords. This is more stretchy and of lower strength. The package never gives a strength number.
For example, for a couple of bucks, WalMart has this lighter and weaker paracord on their shelves.
If you have ever seen, or better felt, the different parcords, you will easily know the difference. If not, let price be your guide.
There's a ton of paracord in all colors hanging in knots in trees all over Yosemite and the Central Sierras. I got a good indicator of how that happened once in an area where we could hang instead of using canisters. After teaching someone the PCT hang, when we got up the next morning they promptly snapped their cord snagging it in a tree against a knot. The broken rope rebounded and draped itself high over a branch.
I've used the Zing It a few times so far - it does not stretch and is designed to glide over bark without sawing into it, and the one time it did snag I was able to pull it out without difficulty.
Technically any cord will do, if you are careful. Mason line would probably work but knots easy and frays. I used to use a polypro rope from the hardware store but it started to wear with the dragging along the bark. I think the zing it will last for a long time, and has the added benefit of being much lighter and packing smaller to boot. You can order it online for twenty bucks a spool and it's useful for guy lines as well.
"In the beginner's mind there are many possibilities. In the expert's mind there are few." Shunryu Suzuki