I found this on the quilting forum and thought you might be interested:
I second CMC's description of the layering process:
1) quilter's cotton (Perhaps use a print to represent the "hand" side.)
2) one layer of regular batting
3) one layer of Insul-Bright, with the shiny side facing toward the "hot" side
4) quilter's cotton (Perhaps use a solid to represent the "hot" side.)
You don't want an extra layer of batting between the hot stuff and the Insul-Bright. You want the Insul-Bright to be able to reflect the heat back from where it came. Putting a layer of batting between the Insul-Bright and the heat would trap the heat inside the layers of the pot holder, so it would gradually build up heat. So that is why I recommend that you create a no-brainer way for people to know which side is for their hand. Perhaps a busy print on one side, and a solid color on the other might work.
Since the item is to be used around heat and flame, I'd avoid anything with synthetic fibers, which would melt and flare. 100% cotton will smolder for a long time, unless it is directly in the flame. Be sure that you use batting that says "100% cotton" right on the package. Warm & Natural is actually 12.5% polypropylene. That's the scrim that makes it possible to place quilting lines up to 10" apart.
Oh, and I think it is a good idea to tell the recipient to never put the item into the microwave. Sparks would fly!
I also read on the warm and company website that insulbrite is heat resistant not heat proof and never use it in the microwave.