Polymer clay steampunk tin by ValerianaSolaris on DeviantArt. She says "I took a simple aluminium tin (size: 11 x 11 x 2 cm) and covered it with Fimo/polymer clay. The clay was stamped, textured, dusted with Pearl Ex pigments and embellished with clock parts. After baking, the whole thing received an antique patina." Further down in the comments section she goes into even more detail about her technique. Excellent.