Erm.. You'd most likely want to use *drumroll* Glass paint.

Yes, they make paints (acryllics, I believe,) specifically intended for use on glass. It has a very, very matte finish though, so you have to use something on top of that, afterwards, to get some gloss to it.

(Just checked quickly - and yes, a lot of it is acryllic based.. I tried calling my mother, since she used to do quite a lot of this - but... they seem to be out tonight. )

What do you want to finished product to look like? Are you painting realistic scenes, or do you want it to look like shiny stained glass? There are several paint options, and it depends on if you want to air dry or bake the finish. There are many brands that will look like stained glass when you are done (and will be glossy) and there are acrylic paints for a more traditional look. However, to get the best finish, you will want a heat cured finish (unless you are doing the "stained glass" look) which are typically considered an "enamel" and are harder to find (Stained glass artists use them for painting on faces and details then they fire the glass before putting it into the stained glass piece).

Hi KarmaGirl, You sound like you know something about what I am looking for. I do wish I had your email address though and I could email you some photos to give you a better idea of just what I am talking about. If you could email me, that would be great and I can forward you some pictures of what I am looking for exactly. You can contact me at: teddytales@woh.rr.com
I am looking forward to hearing from you soon...GemCityJoe