you guys need to think outside the box, a little. the material you are looking for is conveyer belting as used in grain and coal conveyer belts. its an industrial product still in common use, the "ribbing" on the back side is for grip or traction to keep the from slipping during inclement weather. whether you living farming or coal territory you should be able to find used belting either from implement sale or grain and coal processors. or you could buy new from either Goodyear or firestone.