What is black light?

"Written text with UV ink" by Goldflakes, via Wikimedia Commons, licensed under CC BY-SA 4.0.

“Black light” or ultraviolet light is a form of electromagnetic radiation with a wavelength just outside the spectrum visible to the human eye. Its name refers to the fact that its wavelength range begins at the end of the spectrum where the human eye perceives violet light, which is why it is not visible to our eyes. Although we cannot see it directly, it causes certain objects to glow with visible lights, a phenomenon known as fluorescence. It is used in nightclubs to make bright colors on clothing glow, to detect counterfeit bills, as well as fluids or residues in medicine and criminology, or to create various effects in art and decoration.

In fact, there are many more elements than we imagine that are capable of glowing when they come into contact with ultraviolet lights.

What glows under black light?

There are many everyday objects that react by glowing under black light:

• White clothing and other colored textiles after being washed with detergents containing additives that glow under blacklight. In fact, they are added on purpose so that the clothes glow with a bluish-white color during the day under ultraviolet light.

• Fluorescent paints (or UV paints). There is a wide variety of paints for all types of surfaces, as well as for artistic makeup that reacts with black light to create eye-catching designs.

• Banknotes. Several currencies have banknotes with areas that are only visible under UV light, which makes them more difficult to counterfeit and to easily verify their authenticity.

• Fluorescent minerals. Several naturally occurring minerals react to UV lights, including tungsten, titanium, and magnesium, among others.

• Vitamins, especially B2 (riboflavin).

This effect is due to the fact that these substances absorb ultraviolet light and re-emit it as visible light.

In addition to all of the above, many substances used on a daily basis glow under blacklight, such as olive oil, honey, chlorophyll, antifreeze, ketchup, some medicines, the vast majority of postage stamps, certain flowers, and teeth.

How do black lights work?

Blacklight belongs to the ultraviolet radiation spectrum, specifically the UVA range, which covers wavelengths between 315 and 400 nanometers. Although this type of radiation is invisible to our eyes, it has the ability to cause a phenomenon called fluorescence when it strikes certain materials.

In simple terms, when a surface containing fluorescent or phosphorescent substances (such as certain inks, paints, or plastics) is exposed to blacklight, these substances absorb the ultraviolet radiation and re-emit it in the form of visible one. This process causes certain objects to “glow” intensely under this lighting, creating striking visual effects.

Blacklight bulbs are generally manufactured using a filter that blocks almost all visible lights, allowing only ultraviolet radiation to pass through. These bulbs can be fluorescent tubes or specially designed LED lamps, each with its own advantages depending on the specific application.

It is important to note that although black light is a type of ultraviolet light, it is not the same as other more intense forms of UV lights, such as those used in sterilization or medical equipment. Domestic and recreational blacklights are designed to be safe, as long as they are used in moderation and direct, prolonged exposure to the eyes is avoided.

Is black light the same as ultraviolet light?

Blacklight and ultraviolet light are not the same, although they are closely related. Blacklight is actually a specific type of ultraviolet, specifically UV-A, which is found at the less energetic end of the ultraviolet spectrum, with wavelengths between approximately 365 and 400 nanometers.

What distinguishes blacklight is that it is designed to emit UVA radiation in a controlled manner and with a special filter that blocks almost all visible light. As a result, these lights appear as a very faint violet glow, almost imperceptible to the human eye, and have the ability to make certain fluorescent materials glow in the dark. For this reason, it is commonly used in visual effects, counterfeit money detection, forensic analysis, and artistic performances.

In contrast, the term “ultraviolet light” covers a much broader range, including not only UV-A but also UV-B and UV-C. These other forms of ultraviolet light have more energy and, despite being invisible to humans, can be harmful to health if exposed to it for long periods, unlike black light. For example, UV-B can cause sunburn, and UV-C is used for disinfection because it is capable of destroying microorganisms, although it is also dangerous to the skin and eyes.

What is UV light used for

Knowing all the objects and substances that glow under blacklight, you can get an idea of all the uses it has in everyday life:

1. Authentication of documents and banknotes. Banknotes in many countries, and increasingly official documents, include invisible inks that are only revealed under black light to ensure they are genuine.

2. Forensic investigations. It is very useful for detecting biological fluids, residues, and hidden details at crime scenes, which shortens investigation time.

3. Quality control and industrial inspection. Some cracks or defects in materials become visible under UV lights after applying fluorescent agents.

4. In biology and medicine. It is a way of visualizing bacteria, fungi, and other microorganisms or performing dermatological tests, among other more complex functions.

5. Art and decoration. It has become another tool available to artists, who can use fluorescent paints and fluorescent paints in art installations, murals, and other works that they want to glow or look different in the dark. It is also used in artistic makeup and body paint.

6. Events, parties, and shows. From theme parties to concerts to nightclubs, black light transforms the atmosphere by making white or fluorescent objects stand out spectacularly.

7. Model making and creative hobbies. Ultraviolet paint is used in model-making to create striking effects and recreate certain environments in dioramas and miniatures. It adds an extra level of detail and visual surprise, ideal for science fiction themes, magic effects, occult lighting, or secret details on a figure.

Where to buy a blacklight​?

If you are an artist and are looking for fluorescent paint or lights to see its effects, Green Stuff World is one of the best options on the market. We are experts in the modeling sector, offering a wide variety of colors and formats, designed with professional quality and with modelers in mind.

In addition, we have an ultraviolet torch, useful both for seeing the effect of fluorescent paint and for drying UV resin in a few minutes. Whether you are just starting out in the world of modeling or are a veteran of the hobby, working with fluorescent paint and black light will allow you to add a new dimension to your creations.

In the world of wargaming and custom miniatures, blacklight has creative uses when used with fluorescent paint. The most common are the creation of magical details on wizards or fantastic creatures, simulation of radioactive energy in post-apocalyptic scenarios, special effects on bases (lava, plasma, etc.), and hidden runes or inscriptions that are only visible under black light, among many others.