Found on Deviantart.com Cloth effect
I found this while searching for gimp related resources,, I suppose it's an already known technique but just in case.
Thanks Revrock! Easy to do in photoshop too!
Indeed, a few tweaks with some motion blur at 90° and at 180° in Fireworks over the top of the standard grid-1 pattern yield a very effective pattern. Thanks for the spot and nudge!
Worldbuilder, Shieldsmith and Bannerman of Midnight