Map envelopes? Could it get any cooler?
Created by Teevio and inspired by Beste Miray Dogan, now you can make and print your own envelopes with a specified address on the inside. You'd need a nice thick paper so it doesn't seep through to the wrong side, but other than common sense, it's super easy.
You can head to Map Envelopes mini website, put in your desired address and print it off yourself!