Glow in dark pigment, glow in dark powder, 20~30um. Medium glow. Suitable for arts etc. Glow in dark pigment, glow in dark powder, glow in the dark place for hours after charging by sunlight or lamp light, even UV light source for minutes.Material: Strontium Aluminate based.Appearance: Milky crystal powder.Average particle size range: 20~30um.Luminous color: Blue-purple.Free of dangerous, toxic, ...