: Hey Bill, please explain what you mean by this. I'd use the polyester right
: away but I've never used the polyester before and have used the nylon a
: bunch.
: Scott

Well depends on what polyester you'll be using I guess. I tend to only use the aircraft stuff and it's a very tight woven material that's also very light weight. Like any other fabric there are wild variations to what's available. How a 3 or 4 ounce material will behave has little to do with using something heavy like 15 ounce material.

The nylon tends to be stretchy and used as a roof might prevent damage long term. And it's never out of the sun.

Personally I think I'd try the material that Tom Yost uses for his folders in a very light color to help reflect the sun. There are commercially available folding semi-permanant structures available that use a similiar material.

Bill H.