But what does that mean? Well it couldmean you are altering an envelope with art, or you are stamping faux postage on the envelope, or maybe you are trading an ATC, or making a collage on a postcard, or sending a zine, or even shipping a form of naked mail. It is really art that uses the postal system, and not just art sent through the mail.
I have been doing this since my Etsy shop opened. I always decorate my recycled envelopes with my bearpaw stamps. I have also been creating stamps, like the ones pictured, for the use on letters
To me, there is so much negative space on an envelope or box. Why not fill it! Not only does my recipient of the mail get something that looks neat, but I secretly hope that there are some postmen and women who see it and get a little smile at it (or curse my name). It is the emotional response from art, after all, that we seek to invoke.