How does glow-in-the-dark paint work?

Question: How does glow-in-the-dark paint work?
- Keywords:
  chemistry,
  light,
  paint
Asked by Zealousy to Chris on 18 Jun 2015.
- Chris Armstrong answered on 18 Jun 2015:
  
  Glow in the dark paint, is actually shockingly similar to a method of detection of X-rays that I use. So you’re really in my wheel house now.
  
  There are two types (at least as far as I’m aware) one is flourescent based, and downshifts (makes high energy photons have lower energy) UV to the visible spectrum. They generally work on a short scale, and glow brilliantly under black lights. Or Phospherscent which take in visible light during the day and take ages to re-emit the light back out, so when you turn the lights back off they are still emitting the photons (and will do for a few hours)
  
  FYI Painting a tube with glow in the dark paint is a suitable replacement for a lightsabre until someone invents one.

Question: How does glow-in-the-dark paint work?