Where can I get small blue gel lights to put on a poster board size background to aid in a black art effect? Don Drake suggested it for the"Wizards Window/table".

Two places come to mind:

Atlantic Stage Lighting - Baltimore (410)525-2525

R&R Lighting Company - Silver Spring (301)589-4997

Call and tell them what you want to do and they can set you up.

FWIW

Is that similar to rope lights?
Regards, Lynchini

Hi REV BILL,
Blue Gel is a colour filter... I think what you are after is a Black Light - the function of these is to hide all black elements and bring forward white elements.
I also think you require a Cyclorama Light. These are specially designed fixtures which sit at the bottom or top of the "background" and evenly light the area.
So I think you are after a Cyclorama (or Cyc) Light with a Black-Light Bubble. Don't forget that you will need the propper control systems to turn these fixtures on (ie Dimmer and DMX Board, to fade the light up, so the audience doesn't notice it).
Most lighting companies should be able to help you with hiring or purchasing this fixture.
Sincere regards,
Ryan

Look into LED lighting

You can get blue gel filters that will work on various types of lighting.