OK, silly question, but I'm having a hard time finding it on the net.

What is the seat material called? I need to get a bit extra for a project I'm working on, and don't even know what to google to find the stuff. I've got the S (I think the OR has something different).

If anyone knows where to get a few scraps of this stuff, that would be much appreciated as well.

Cheers,
--Fishhead