Twin Size Stellar Glow in the Dark 3-piece Comforter Set. The set includes comforter, sham and bed skirt. Moon and stars glow in the dark. Face of comforter and sham is 100-percent cotton and the glow in the dark material is a mineral, not a chemical. The glow affect is activated when the material is first exposed to light. The back of the comforter, sham and the bed skirt is made of 100-percent microfiber polyester.