Here's a neat trick for light boxes that go behind art-glass panels. I do a lot of free-standing pieces that are essentially light boxes crafted of fine woods, and then fitted with an art-glass panel. On all of them, to scatter the light and give an even-as-possible reflection, I use heavy-duty aluminum foil as the reflecting surface. I cut a piece about 20% bigger than the panel to be covered, then softly crinkle it up into a loose ball. Then carefully open the foil again and gently flatten it onto the back panel until it is smooth but don't "iron out" the crinkles! Then I spray the panel and the back of the foil with spray contact adhesive, let it dry and then smooth the foil onto the panel. Trim off the overhanging foil with a razor blade and you have a prefect back reflector to enhance your art glass. For my lighting, I use well-placed standard compact fluorescent light bulbs, as they last a long time, produce any kind of light you need and produce very little heat. Some of my backlighted pieces can be seen here:
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