[MeekOneGOP]

This is the effect that makes black-light posters work. They were popular in dormitories when I was in college. (Which probably dates me!)

---

Dates me too, I guess! ;-)

And it took me all the way to "blacklights" to have any idea what you were talking about! LOL
. . .(and then, only in an intuitive manner!)

[sawsalimb]

lol-pointless sidebar regarding blacklights. Tanqueray gin radiates a beautiful blue color when illuminated by UV.(Other brands don't do it,at least that I've found). It's hard to look suave at a nightclub when the drink that you're holding is glowing in the dark.