I have tried attaching the led light strip to the perimeter of the box with little success, though many do that. My experience has been that I see "hot spots" through the litho, and insufficient illumination. I prefer to run the strips in parallel lines on the board behind the litho. This process use more lights, but they are not costly. I also use a 12V A/C adapter with all my lithos. I buy 8X10 shadow boxes at Hobby Lobby for about $12 when they are on half-prce sale every other week. Can't build it that cheaply. I line the backer board with silver foil. I estimate that I have approximately $45 invested in each litho, and sell them for $150. Below are pictures of a sample of my lithos. (sorry about the pictures that should be rotated. I don't know how