Painting on Glass

[Mary Sparrow]

Has anyone here ever painted on glass? I have been asked to paint a portrait on a window. I have a client that used to live in California who had an artist paint portraits of her two girls older on old windows, I know it sounds odd, but once I actually saw them they are really beautiful!

Imagine an old window with the paint chipping off used as the surface and the window casing is the frame. It is long and narrow with six smaller panes at the top and one long plain piece of glass on the bottom, all of the glass has been turned into a painting with the girl in the bottom as if she is in a garden so that it looks as if you are looking through a window at the child in the garden. It still sounds a bit odd to describe and if I get a chance to take a picture of it I will share with you.

At any rate, she is wanting one done in a similar manner of her third daughter. After examining this window from behind, it looked as if the back of the window was sprayed with a thin layer of something sort of speckled. Looking through that, it seems there is another thin layer that I believe to be on the front side of the glass like some sort of primer. Then the painting itself which has a high gloss varnish over it.

I put off meeting with this lady for a long time because all she kept saying was come paint a portrait on a window. But now that I have seen it, I REALLY liked it and wouldn't mind trying it, but am unsure of what needs to be used to properly prime the glass. Any thoughts?