Anotehr thing about neon's (and this is a bit dated so may be no longer true), is that the flourescent colors they use DO actually glow BUT...They also tend to die in sunlight fairly rapidly thus not lasting all that long.

trivia:  "color brighteners" that are added to laundry detergent are actually flourescent dies that glow.  Check out that white shirt next to your Peter Max poster under the black light!

Dan (I gotta get building and stop yacking!) Newland