Udaipur is famous for its miniature paintings. You can find them done on silk, paper or sometimes camel bone. It is rare that you will find new paintings on camel bone (those have to be very small or joined). If the artist is honest, he will tell you that it is on 'synthetic camel bone' otherwise known as 'plastic' to the rest of the world. You will soon get your eye in on quality and be able to spot bad and/or mass produced stuff.

Don't buy the first thing you see and never pay the first asking price, which is just a starting point in an expected negotiation. There is always a little room to bargain prices downard, but not much if its with a genuine artist.