Sorry it took so long, been a little busy and the answer went back and forth a bunch of times. Unfortunately, stronger is a very generic term. In the fabric world there are all kinds of things that are tested.
weathering including uv, hydrostatic, and others
and all these things can be measured before or after finishing.
In my opinion #8 canvas is more “durable” than the wax fabric by the simple calculus of heavier cotton yarns and shear weight.
i was running out of time so i thought about it and went ahead and ordered the F3X black, knowing me, i will soon order it in sand, and olive.
i know have 12 bags of all types and brands, and funny thing though, the Domke f3 is still the only functionable one , the rest i am going to burn.
Don't get me wrong, the F3 waxwear is a great colour, and i still love it. hopefully you will bring it out in the #8 canvas, [B][U]i wont mind paying the extra cost.[/U][/B]