Bottle caps.

[Imwashingmypirate]

We don't put our shopping bags in the recycling. Says on the wheeliebin not to. So our plastic bags are bags for life so you can reuse them and then take them back and they will swap them for free. They also cost 40p each. The coop has biodegradable shopping bags that look and feel like plastic. They are 10p each. We have a cupboard full of the fabric or recycled large plastic bags which I always forget to take with me. The 40p ones, I've never exchanged. We use them as little bin bags which go into the non recycling waste. The large fabric ones can range from 70p to £5. They are handy for a beach trip. Or taking snacks on a picnic.

[Imwashingmypirate]

I just double-checked and confirmed that our local recycling service doesn't even accept bottle caps. I wonder how typical that is around the U.S.?

Ours didn't til recently. They fall through the machine and end up either incinerated or in landfill. That's why they need to be attached.

Edit: ok I don't actually know this for sure... I'm sure I watched a recycling documentary but I can't fact check it.