Many US supermarkets use very thin plastic bags. I'm guessing 0.5 mil []. They're noticeably thinner than the type you (used) to get from UK supermarkets. This

Many US supermarkets use very thin plastic bags. I'm guessing 0.5 mil []. They're noticeably thinner than the type you (used) to get from UK supermarkets. This site suggests that "reusable" type would be > 2.25 mil. https://1bagatatime.com/learn/what-is-a-mill/ https://1bagatatime.com/learn/what-is-a-mill/