Think I'm getting closer on this bar bag. Idea is to make it easily accessible while riding, fast to attach/remove and NON-waterproof so it can be washed and dried after carrying food on long rides. I first tried using heavy weight canvas to get it to hold its shape, then tried sewing a couple of rare earth magnets into the hem for soft closure, and finally put a fidlock magnetic snap on it with some closed cell foam for structure.
Also made a load (~40) of these saddle bags while out of work during summer, sold and donated the proceeds because #2020. Very basic but easy to color match the zipper which some like.