bytebold

Hi, i try to make my own pyramide- inlay in a RG- neck. The cavities are routed and the acrylic plastics are ready for mounting. But... what material is needed for the background of the acrylics? I thought to print it on fotopaper, to cut it and put it in the gravities. I heard, that the photopaper will bleach out. Is it a option, to print the pyramids with a colour- laserprinter or what solution is the best ( and simpliest )? i think, the colour has to be stable for 75 years. Thanks, bytebold