Thread: Plexiglass tint?

I forget where it was, but awhile ago I remember reading a thread where someone said you could purchase a special paint to spray on plexiglass, and the plexiglass would look completely opaque until you illuminate the "case" from the inside. I am interested in purchasing some of this, if any of you might know what I'm referring to.

I was thinking of wiring the hdd activity light to a blue cathode light then inside the case with a solid state relay or something of that nature. It would then produce a somewhat random on/off effect

thanks!