I've been trying to rework this concept over and over in my head. This is just a prototype and as we speak I have ideas to make it better. It fits a one gallon zip lock bag, which when turned inside out, creates a stiff rim at the top. What I really wanted was for the hem that turns inside the bag to be longer and have some stabilizer attached so that when a zip lock bag is inserted inside the holder, the hem will keep it in place. As it happened, the hem is too short and I didn't have any stiff Pellon stabilizer when I sewed this. I even considered using boning around the rim but it doesn't seem to need it. The inside out zip lock provided enough stability to keep the bag open but I actually machine basted the bag inside the holder. I can remove the plastic bag with just a few snips if needed. It's not what I wanted, but for now it will do the job. It is tied to the underside of the lid of the center console of my truck to keep it in place. Oh well, back to the drawing board.