This is a bit of a tangent from my main focus but I feel its pertinent to the process. I always, always recommend Sunbrella Fabrics. They are the best outdoor materials you can find and they use Tenara® Sewing Threads. Sunbrella originally made materials for marine boats and then applied this same technology to outdoor furniture. Watch what happens when this 3 year old dirt-caked sofa is cleaned with a pressure washer.