The picture has nothing to do with the post but I did LOVE this lamp we saw in New Mexico.
A friend recently asked me about making buttons out of clay. I found the link that has the technique for making tiles which could easily be applied to making buttons.
There is a link within that page for basic polymer clay baking information and how to prepare the clay.
This will take you to the article on painting the tiles or buttons with glazes. Hope this answers your questions.
Let me know how this works out for you. Making buttons is on my TO DO list.