Deerskin and Birch smoke
Heres some examples of my previous project, images of roe deer and birch trees made entirely from themselves in the form of parchment, birch wood smoke and birch tar smoke. The size of these images doesn't capture the detail of the viens on the surface of the skin so feel free to email me for larger images and having said that my computer monitor ruins the colour of the smoke as well! Its taken a couple of years to develop this technique but I'm really happy with the results, they take ages but are enjoyable to make. I've had to give up on them now due to eviction from the Birchwoods I was set up in.
See the whole process here http://www.youtube.com/watch?v=5DCA_2VuSP4