What kind of clay works with paper mache?

I want to make a joker mask as seen here....a href="http://www.aintitcool.com/images2007/JokerMask.jpg..." rel="nofollow"http://www.aintitcool.com/images2007/Jok…/a but what i was thinking would be to use clay to make the face and then use paper mache to cover it and make the actual mask. I was thinking of making the paper mache with wall paper paste instead of flour just so it would be stronger and such. But what i was wondering what kind of clay would work so that the paper mache would just come right off instead of having to break the clay if it hardened. I would preferably like to have an air dry clay or a clay that i could put into my oven to bake instead of having to have a kiln. Thanks so much to anyone that can answer. If you are not sure just give me what you think and if you can think of some other way to do it so that the paper mache will come right off please suggest that... Thanks sooo much.