This cute little fish was done as an experiment with repousse and chasing. Repousse is a metalworking technique in which a malleable metal (in this case Coke can aluminum) is ornamented or shaped by hammering from the reverse side. Chasing, on the other hand, is the opposite - hammering the metal down from the front side. When they are used in combination the result is a relief image that is somewhat sculptural. The ancient civilizations of South America used these techniques a lot with gold and silver foils and made some very striking artwork ornaments. The more malleable the metal, the easier it is to get good results. The Coke can aluminum is not as malleable as copper or gold but is available and free.
I have done this image very roughly so as to give it an abstract feel and then enhanced it with color from felt tipped markers. This is fun and reasonably fast. I want to experiment with it some more as I think some fossil images could be done with interesting effect with this technique.