This fad of drawing on envelopes started back in my twenties. My friend Steven and I were always busy so we decorated envelopes and posted them to each other in Toronto, I will remind you this is prior to cellphones or email. Steven passed away in his twenties and so did the correspondences. Years later while in Japan I started back using envelopes to draw on and write letters to myself and post them to my home… besides individual envelopes I would do several as a series. like sketching all the bridges or the many different varieties of trees along the Kamagawa River in Kyoto.  One trip to Japan I had sketched over 25 envelopes, every few days I would go to the Japan post office select an appropriate stamp and post a few, after ten days I returned to Singapore. Then I checked the post and saw a large sealed envelope from Japan. Apparently, the Japan Post office staff collected all my individual envelopes and stamped them and placed them carefully into a plastic bag and then into a Japan Post envelope and mailed them to me. I always received the ones from Japan or Singapore in great condition but many others were lost.