Highly UV reactive Invisible Transparent Lacquer based paints. They go on completely clear and when subject to a black light emits a very bright illumination of the chosen color.
The Transparent Blue UV paint can be used with most any range blacklight but the Transparent Red and Green require true 365 nm range black light. Anything higher will either hinder or even completely stop the UV response. Using a true 365 nm black light gives you the best fluorescent lighting effect with UV paints.