The silver emergency blankets they sell at Walmart will tear to shreds if they get a puncture, but the SOL blankets won't.

On the downside, the silver reflective on the SOL blankets wears off. The Walmart silver blankets won't lose their reflective surface.

I believe the Walmart blankets are made from "Mylar", which is a brand name for a type of plastic, not all of which is shiny and reflective. It's not very stretchy, but it tears easily.

The SOL blankets are made from high density polyethylene (HDPE). It tends to stretch instead of puncture and tear.

SOL makes several kinds of reflective blankets, some are quite a bit heavier than others. Those heavier blankets might make a decent ground cloth.

I use a piece of bubble foil insulation with a reflective side for a ground cloth. I also fold it up and use it for a sitting pad. A piece of that with a fleece blanket over it would be pretty nice to sit and lay on.