I used an e-blanket, though it was far more than a dollar, as a ground cloth on some desert backpacks. It served a second purpose as a sun shield, as my wife doesn't fare well with heat at times. It acquired lots of rips quickly. I've had better luck with crossed linked polyethylene , sold as polycryo, or patio door insulation. You need the 1.5 mil, not the .75. This is pretty durable and a few ounces for a solo groundsheet. I'm guessing the dollar stuff is meant for one use and would be in the trash very quickly.