Growler,yes,that's what I used,I made sort of an Eagle(
)freehand and made different color squares around the window,I loved working with that stuff.
That was several years ago and it's now gone,but for a while it was like an addiction,I used it on clear vases,mirrors almost anything it would adhere too
I was looking for a pic of my door-window can't find it...I was surely not as good at it as you though.