I have recently been making some table protectors, which other people call table runners but which I line with Warm 'n Natural, one or two layers, to protect from hot dishes.
I let myself get convinced that I should be using Insulbrite, so I bought some and tried it with a lovely batik topper. I learned two things: 1) it is not really "quitable" - it has no give, plus it crackles - and 2), the mylar in it seems to be making tiny cuts in the fabric that wraps around the edges of it. At least that's the only reason I can see for something that has never happened to me before.
So, maybe it is fine for pot holders or mug rugs, but my experience says don't try using it for anything much larger than that.