You may think I'm crazy for stamping on my windows, but really it's is very simple to do - I used acrylic matte medium, applied to the stamp with a brayer. I don't know if you can see it well enough, but it looks like etched glass. It isn't hard to remove, either - it will come off easily the next time I wash my windows, as the matte medium dissolves easily in water.
The cloisonne stamp is perfect for this technique, because of the bold lines. What a quick and easy way to add a holiday touch to my home!