One of the older envelopes that I sent out to José vanden Broucke in Belgium. I already worked a lot with acrylic paint then. If you are interested in seeing more outgoing mail-art I suggest you Google for my name and the subject you look for. The complete set I sent out is thousands of envelopes large and is all over the earth. I documented a lot to in digital form and that is placed on blogs that were started over the years. See for a good start the old IUOMA blog that is hosted at blogger.
You can access that here: