Self-luminous Paint

Luminous simply means giving off light; most things in our world produce light because they have energy that originally came from the Sun, which is the biggest, most luminous thing we can see. Strictly speaking, although the Moon appears to give off light, it’s not actually luminous because it’s simply reflecting light from the Sun like a giant mirror made of rock. Luminous is quite a vague word really. Arguably, even a flashlight bulb is luminous, because it turns electricity (electrical energy) into light and shines it toward us. But bulbs like this are incandescent and make light by making heat. Luminescent things, by contrast, make light when their atoms become excited in a process that needs little or no heat to make it happen