Does anybody know what is the difference between polyester felt, and polyester fleece, such as Armo or Thermolam?

Other than the width?

I've only been wondering for about five years now... :)

I really don't know, but I just checked some Wikipedia definitions to make sure I am generally on the right track.

Felt is simply fibers that are compressed together, not woven. That is why, in general, felt cannot stand up to washing.

Fleece is a woven fabric. Polyester fleece is woven of fibers made out of polyester fibers that have a nap. Because it is woven, fleece can be washed.

thank you, that's interesting, I wouldn't have thought to look it up.

peel