I've been using one for a while also. Just folded in half and added some shockcord to channels at the ends and a long piece of shockcord along the edges so I can slide it and adjust it under the hammock.
Very easy and cheap UQ, has kept me plenty warm so far, with a 2-season sleepingbag in early spring and just a 1-season summerbag the last few months.
Would agree that a pad is needed for colder weather.
I didn't sew mine up, to keep it more adaptable, but sewing will add some warmth as it can be closed off more efficiently, and still be made with an opening for a pad.
It's been a great piece of kit. Packs down reasonably small as well. Folded and rolled I can fit it in a 12"x6" compressionsack and compress a bit more, an inch or two lengthwise.
Recommend for a cheap way to get started on that UQ-thing.
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