By Donita H.
Not exactly sure what you're wanting to do...but you can paint on windows using craft paints. I did that for years on my classroom windows as a preschool teacher. I never liked cleaning the windows later on, but loved the effects of the paint. If you're wanting a 3D effect, you could tape cut outs to the window and then paint around...
How can you make a Santa looking out a window? I would use a white crayon to transfer my drawing to the window. You would need to keep in mind which direction that he is to face. You could also draw on paper the size you want the Santa to be and tape it to the inside and trace with a white crayon from the outside tape the picture on the outside or the inside depending on the weather.
I use tempera paints that you can purchase from any craft store. Michaels and Hobby lobby do coupons online. I would also add dish soap in the paint to make it easier to remove. They also have window paint if you don't want to trouble with the regular paint, and it may cost more. But that is how you would paint your Santa.
What materials are you using? I'm not clear on your question.