Nicholas asked 3 years ago
What colors glow under black lights? Why are these colors typically chosen for band t-shirts sold at rock concerts? Why are black lights sometimes called UV lights?
William Bryan Staff answered 3 years ago
What colors glow under black lights?
Black light paints are available at some stores, but they can also be made. All you need is glowing paint and clear nail polish. Add the paint to the glue mixture of the nail polish before it dries. This usually turns out best if done with a neon colored glow in the dark paint and white or pink nail polish, as black tends to turn purple or blue under a black light. With nails painted this way, even your clothes will glow under a black light!
Under a blacklight, any color that does not contain fluorescent dyes will appear very dark because no visible light will be reflected back to your eyes from those objects or substances. For example: Blue, Green, Black. Most objects you can expect to glow are colors that are very bright in regular light – reds, oranges, yellows. Since most of these objects also contain fluorescent dyes, they will actually appear pale under a blacklight since the fluorescence is the same color as the object itself. For example: Fluorescent Red/Pink, Orange, Lime Green. There are exceptions though… we have an article on this.
Why are these colors typically chosen for band t-shirts sold at rock concerts?
The bright colors are chosen to help the band “stand out” against the dark background of the club.
Don’t forget that anything made with white or pale fabric will look grey under a black light – including your clothes! So even though your t-shirt may appear bright red in regular light, it might actually be grey if it is 100% cotton. The best way to find out would be to check it out for yourself at a concert.
Your shirt will not glow as brightly if it contains fluorescent dyes unless you let those dyes dry completely before exposing it to ultraviolet radiation (which is what you get with a blacklight). The biggest issue with using clothing as “blacklight paint” is that most textiles contain fluorescent dyes.
Why are black lights sometimes called UV lights?
Black lights are sometimes called UV lights because they emit light in the Ultra-Violet spectrum. This part of the electromagnetic spectrum is just beyond what our eyes can see, right before X-rays. The first fluorescent material was discovered by accident in 1854 when it was noticed that invisible rays coming from a uranium salt made certain painted wood blocks appear bright under natural daylight. By 1861 these so called “Becquerel Rays” were identified as having originated from within the uranium atom itself and ray particles were given the name “Ultra Violet.”
UV lamps produce ultraviolet radiation which blacklight paint absorbs to create visible light emissions or fluorescence.