Found it at ikea... It's a spun polypro shell, yes, like you see on ultracheap laundry bags.
Lots of stuff is made from this, and as long as you have a tarp blocking any major breeze, a twin size of this, folded in half would probably make a decent summer-weight quilt.
IMHO, it's much heavier than a poncho liner, but is bigger too... I resisted the urge to buy it, but it'd be fun to play with...
I did make one cool find. In the kids' bedroom section, they have a net-curtain ..
$5 for 2 == 110"x98".. should be big enough for a bugnet. it looks similar to tulle, only much stronger. It won't stop no-see-ums, but it will stop mossies... It's white, but I've had a lot of success with spray dyes, which are also cheap.