This material is very tough - you cannot pin it - I used tape and strong clips. I did French Seams - waaay not necessary - perhaps a zig-zag would have been OK as well. It was difficult to turn the bag inside out, right side out. I also cut out the lower corners, as opposed to just folding the triangles up to make square corners. On the bottom, I offset where the black strap crosses - it was getting tough sewing! This one is NOT lined - not necessary. Before construction, I washed the bag material in the kitchen sink with a kitchen scrubber and warm water.
If you press this tough material with an iron, between waste fabric, it melts, crinkles up into an unusable glom. (Someone will probably find a really good use for glom and make a million $$$.)