Luminous paint

Luminous paint or luminescent paint is paint that exhibits luminescence. In other words, it gives off visible light through fluorescence, phosphorescence, or radioluminescence.

Fluorescent paints offer a wide range of pigments and chroma which also 'glow' when exposed to the long-wave "ultraviolet" frequencies (UV). These UV frequencies are found in sunlight and some artificial lights, but they—and their glowing-paint applications—are popularly known as black light and 'black-light effects', respectively.

In fluorescence the visible light component—sometimes known as "white light"—tends to be reflected and perceived normally, as colour; while the UV component of light is modified, 'stepped down' energetically into longer wavelengths, producing additional visible light frequencies, which are then emitted alongside the reflected white light. Human eyes perceive these changes as the unusual 'glow' of fluorescence.

The fluorescent type of luminescence is significantly different from the natural bio-luminescence of bacteria, insects and fish such as the case of the firefly, etc. Bio-luminescence involves no reflection at all, but living generation of light (via the chemistry of Luciferin).

There are both visible and invisible fluorescent paints. The visible appear under white light to be any bright color, turning peculiarly brilliant under black lights. Invisible fluorescent paints appear transparent or pale under daytime lighting, but will glow under UV light in a limited range of colors. Since these can seem to 'disappear', they can be used to create a variety of clever effects.

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Wikipedia