I made an emergency air mattress by taking a 42 gal. industrial garbage bag and stuffing it with a large number of plastic shopping bags (the kind you get at the grocery store, Walmart's, etc.) I made puffs of the small bags, by stuffing the small bags into eachother. Then I threw the puffs into the big bag. I tied the two ears of the big bag so I had an opening at the top to let air out. I kept stuffing the small bags into the large one until it was pretty thick, then laid it out on a table and pushed some air out and got it level. It was really comfortable to lay on, on the ground. I would prick it where more air needed to go out. I can roll it up into a bedrole about the size of a regular one, but it hardly weighs anything. I wish somebody could do this and check out how long it lasts with daily use in the woods. Be sure to use the 42 gal. even tho it's harder to find.

Welcome to the forum. This sounds like fun, if nothing else and recycling plastic into something usefull too!