These are my favorite bags -- they have hooks on the two sides that allow them to "spread across" a grocery cart -- people are always asking me where I got them. I've had mine for years, and they're still in excellent condition.
https://www.walmart.com/ip/Reusable...MIi-3mwI3M5gIVFmKGCh18oAfBEAQYBCABEgJYpPD_BwE
As for the discussions above, I'll add these thoughts: If you're going to sell these bags, they have to be better than the ones that're available everywhere cheaply. So focus on GOOD features.
- My favorite bags are the ones that have two sets of handles -- one long for over-the-shoulder /one short for hand-carrying.
- Style the bags so they can fold flat -- preferably they'd be secured in a folded position. With velcro? With one of the handles?
- Yes to washable -- or at least easy to "wipe down".
- You want a bag that's big enough, but not so big that it's hard to lift when full.
- Consider a solid bottom (removeable?) that'd allow the bags to stand up on their own.
- Include a flat pocket that'll hold your wallet and/or phone while shopping. And another pocket for coupons.
- If you have Aldi's in your area, include a small "keep a quarter" pocket; it'd be nice if this pocket were secured with a bit of velcro.