I have actually looked through the book while in B&N. It is really interesting, and amazing what these cats look like after the painting. They also list the ingrediants of the paint that they use, and they all seemed non-harmful to the cat should they lick the paint off.
What I couldn't figure out was how they would get a cat to sit still long enough to actually do the painting. Some of them were far more detailed that the bum painting and the cover painting. I guess you just have to have a mellow cat or a whole lot of patience.