Just read a tip in Ready Made magazine about putting up bubble wrap on a window with tape to mask a bathroom window. I am going one step further. Because bubble wrap also has insulating qualities, I am putting it on a window that needs to be insulated for the winter. To make it decorative, I am going to color in some of the bubbles in a pattern with permanent marker to create a "Stained window effect" - (Great for the kids to do?) PLUS I am utilizing recycled bubble wrap from mailings I have received. So cost = $0