yay! I have six prototype playmats with me, but it's rather difficult to explain in English what kind of material these playmats are using so I write: made from a kind of cloth/banner material (I think it has some rubber material mixed inside)
(also, are you saying that you haven't actually seen the playmats?)
now, how do i get these? The Upgrade Pack is $38 (the explanation is on the project page). If you want the Upgrade Pack, add $38 to you pledge level total.