... crystal powder.Average particle size range: 20~25um.Luminous color: Red.Free of dangerous, toxic, heavy metals, radiation. Friendly to human ... (glow in yellow-green, blue-green, sky-blue, blue-purple, red, orange, etc.)2. Glow in the dark plastic products: printing ... photo paper, film, sheet, plate, pebble / stone, garden lights, etc.3. Glow in the dark ...