Luminous paint

Luminous paint (or luminescent paint) is paint that emits visible light through fluorescence, phosphorescence, or radioluminescence. In the early 20th century, radium paint was often used to create a luminous glow. The usage of such a material led to the deaths of many, most famously the Radium Girls. After the discovery of the adverse effects of radium exposure, many countries banned the usage of radium paint.