Have a look at this Japanese artist's work. He paints in 3D using layers of resin! You have to watch the video to appreciate the technique.
http://www.thisiscolossal.com/2012/01/riusuke-fukahori-paints-three-dimensional-goldfish-embedded-in-layers-of-resin/?src=footer
http://www.thisiscolossal.com/2012/01/riusuke-fukahori-paints-three-dimensional-goldfish-embedded-in-layers-of-resin/?src=footer