Agree about the closures ripping apart after a few uses.

BPL had a study using police dogs who picked out the lockers containing drugs stored in OP sacks every time. However, when I tested my late dog using dry dog dog food in freezer bags (even I could smell the dog food through the freezer bags) vs. OP sacks, the dog ignored the OP sacks and went for the freezer bags. Of course my dog was not trained to sniff out drugs, although he was highly enthusiastic about dog kibble! Bears and mice have a more powerful sense of smell than dogs, too.

Some think these are better, or at least more durable and less pricey: Nylo-barrier odorproof bags. I haven't tried them yet, because I still have a bunch of OP sacks left. When their closures give up the ghost, I'll try these others. However, I use them inside my Ursack.