I used a technique from Donna Kato on the Carol Duvall Show to trasnfer images onto polymer clay.

I did a Google search for French advertisements from the 40's and came up with some of these. The last one is just a floral pattern I stumbled upon in a Japanese font I downloaded.

I found some photo paper from Fry's that would tend to run on sale for super-cheap and it worked the best for me. The white was brighter when it transfered. Lots of trial and error, but definitely cool to play with.