Ditto to all above.
He's got different materials available, depending on what your needs are; weather, snow load, under a roof etc. We got ours in Sunbrella, since rain is more of a concern than snow load here; the Sunbrella 'breathes' so less mold. The Aqualon is more water proof and will take more of a snow load w/out as much stretch as Sunbrella, but does not 'breathe". This is all per Ed(?), the owner.