For the reverse, I used alcohol inks to create a Tokyo manhole cover. The manhole system in Japan is world renown and the Japanese people take extreme pride in them. There are many special covers and many covers are designed specifically for the local market. There are an estimated 6000 manhole covers in the country of Japan. If you want to find out more and see pictures, please visit here.
To add interest to the reverse side, I found some amazing used NY postage stamps from my collection to tie the front and back together.