This year Eric has a mail art call to recycle paper bags into mail art.
You can see the ones he has sent and received on his blog.
Here are two more that I sent him recently.
And here are two very nice ones from him in return for ones I have previously sent. The one from the Body Shop has a wonderful stamp on it, and the one with the space-themed washi tape has a great personalized stamp Eric designed.
What's the strangest thing you've turned into an envelope?
Do you have paper bags that you think would make good envelopes?