Hi. Using came for a window is not a hard set rule. It really depends on the design of the window. In this video I was creating a craftsman style window with geometric shapes which is best served by came as it gives nice straight and unified lines. But, if I were building a window with an artistic design I could/would use foil. Which ever method is used, it's very important to wrap the piece in a Zinc U channel for stability, as I did in this video. Glad the video helped you and thank you for commenting!