Lots of respondants didn't really read the WHOLE question, got as far as "pot holder" and glommed on to Insul-Brite.
Our poster states it's used for ironing board covers. I've used it for ironing board covers, pot holders, oven mitts and (ta-da!) jar covers for those jar blocks (I used my pintuck attachment to create the ridges in the canning lids).
I've always known it as teflon fabric, and have bought it quilted and UNquilted.
Here are two weblinks to the Nancy's Notion's website for both items, which she markets as "Iron Quick":
UNquilted:
http://www.nancysnotions.com/product...uick+fabric.do
QUILTED:
http://www.nancysnotions.com/product...uick+fabric.do