This isn't my idea it was sent to me in an email.
It also doesn't use hexagons but you could probably use them just as well.
It works well for glasses when they "sweat" in the summer.

Thanks for the post. Interesting concept.

Love the coasters. Thanks for the tute. I'll be making some for sure

Thanks for this link..

With all those layers of fabric if you put a layer of batting I bet it would make a great hot pad, or oven "mitt"

So these coasters don't need batting?

The video didn't show any