"I have a spool of thread on my desk labeled 100% cotton quilting thread. It is a very well known brand, widely available, and is one of the top selling machine quilting and piecing threads. It is twice as strong as a comparable polyester thread. Although it isn't labeled as such, it is coated with a glaze which strengthens the cotton fibers and makes the thread rather wiry."
Just wanted to mention (as a sewing machine mechanic) that you should never use a hand quilting tread with the glaze finish in your sewing machine. That one is not a myth. I have seen some very frustrated ladies with that on their machine. No way to get a good stitch, for one thing. And it pulls the needle into the hook and will put burrs on it. That wiry stuff has a mind of it's own, and doesn't comply with what the machine needs it to do.