Not that big a deal, just using blacklight to backlight uv reactive bubbles. First results. UV reactive bubbles with flash and blacklight (underpowered AA battery blacklight) Soon I plan on a different backdrop and a real 110 volt 24 inch tube blacklight for better illumination. Anyway - if someone could give me a rundown on creating a pure black background in PP I'd appreciate it. Any experiences, tips or information to improve upon this is appreciated.