This was built as a practice for a bigger more complex RGB LED Infinity Mirror, kits for a similar Infinity Mirror can be found in the Store or More Info
The front piece is Plexiglas covered in a sun film. Both sides are reflective, one more than the other. But its still transparent. The back is another piece of plex the same size, covered in a completely reflective mylar film. They were both purchased surplus for maybe $0.50 a yard. It came with no adhesive coating, so I mixed some corn syrup with water and rubbed the film smooth onto the plex, let dry overnight, worked better than I thought.
LEDs are then suspended around the perimeter in the middle of the 2 mirrors. They are all wired in parallel and are powered from a Simple Constant Current Regulator and a 5 volt power supply. The gallery has a layout diagram that helps explain.