Wanted a way to test colors for light boxes. The test disc has thicknesses varying from 0.2-1.4 mm. I just used a small “sewing” light for the inside. first plate has the test disc, I add a 1 mm text in Bambu studio with the filament info. second plate has the disc holder with spaces for 22 discs, and the “light box”. very handy for testing differant filaments and thicknesses for color shades.