Hi, I'm new to MYOG. My first attempt at a top tube bag came out okay, but would be better with stiffer side panels. I thought something like 1/8" closed cell foam sandwiched between 2 layers of fabric would work, but I'm having trouble finding the right material. What do you use, and where do you get it? Do you have any related tips you can share? Thanks.
Use EVA foam. It is durable, does not absorb much water and keeps its shape. I'm talking to you as a bag manufacturer.