Use the Reusable Shopping Bags.
I made a donation to our local public radio station and the thank you presents that arrived in the mail were 2 nylon reusable shopping bags. I have since shopped for these items and have yet to find comparable open to closed size ratio. I can fit about 3-4 plastic bags worth of groceries in this bag and it takes up no more than 3 inches in my purse or comes with a small clasp to attach it to belt loop if needed. It has large arm hole to easily throw it on your shoulder. And, here’s the key, I always have it with me. I have have plenty of the thicker boxy type lining the trunk of my car wondering if they will be used for groceries again. Many localities are beginning to tack on bag taxes to encourage, reusable bag use and discourage unnecessary bag use. The amount of plastic getting into our water and food chain is frightening. If you don’t do it for your own health please consider doing it for those of your children and grandchildren. (And Note: it was my daughter who asked me to post this cheap trick)