Yes its cloth. Because of its weave it will be stronger.
But not really wanting to put a damper on your purchase if they used common resin you are going to see them buckel and change shape with heat , ie sun

I dare say if you put it under hot tap water it will deform and recommend that you dont use them as you will have no seal in the rain.
Ask if they used a polyester or a vinyl ester ( DOW chemicals )
Polyeter deforms approx 50 degrees celcius and vinyl ester about 180 degrees celcius.
Big difference ! Think Maclaren F1 They used it and so do i on anything i make.