I bought some dyneema from an outdoor store that looks identical to the blinds string everyone is talking about. But it is not nylon so it doesn't stretch. I think it is about 1 mm cord thickness. I think I paid $6 for 500 ft. The string really didn't have a brand name. I used it this weekend for my adjustable tarp ridge line. I put two prussik knots on either side to hold the tarp on. They were easy to adjust, and held great. I also tied tautline hitches to the pull outs and they held as well. Oh, and I used a figure 9 to tighten it. It was the smallest figure 9 I could find, and the string didn't pull through. I am very happy with it. Of course, I couldn't tell you where to get it, unless you were in Utah.