Believe it or not, my preferred backround is car window tinting. My husband is an expert at applying it and we seem to have it laying around the house a lot. You can buy car window tint at walmart for pretty cheap. You want to get the darkest you can/ limo grade. As long as you apply it right (on the outside of the back glass) it never gets bubbles, won't slide around, looks very smooth, there is no taping and it will be permenent until you decide to take it off.