I know there are many places to buy nylon/ripstop. I have bought some at Joann's with some 40% off coupons, they just sent me a 50% off coupon. Even if you are just starting out and want to 'try' some projects, their ripstop is normally $6.99/yard. This coupon is for a single cut. So you can buy 200 yards of one color if you want. You can print out multiple coupons and go back a couple of times, whatever works for you (my wife makes the same trip as me and she and I each get what I need and purchase separately).
My tests have shown me that it is waterproof. It is probably around a 1.9. I am 240 lbs and it holds me in my hammock with no problems.
I just got back from an overnighter in which the temps got down into the low single digits and did not have any issues with sweat/condensation in the bottom of my hammock or sleeping bag. I had an UQ and I was in my backside -40d down (800 fill) sleeping bag.
Enjoy!!!
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