I sewed myself a set of front panniers a long time ago. They're still nice panniers, except the coating is peeling off the nylon and one has a small hole in a bottom corner. They're a bit of a mismatched set because they are 2 different shades of green, and one has a nice pocket on it and the other doesn't, and they have different zipper gauges. Guess I was working with whatever material I happened to have around at the time. The plastic stiffener against the back was a plastic shoe mat. Bought some nice aluminum hooks for rack attachment - think I've got an extra set of those hooks laying around (maybe for the rear panniers I never made). A couple aluminum bars inside each for mounting stiffness. One of my more useful sewing projects.