Ever since there was any kind of currency, there have been people who tried to falsify this currency and get actual value for fake money.

Throughout the human history, coins were the basis of our monetary systems, making counterfeiting a lot different than it is today. In that time, the percentage of precious metals like silver and gold was altered to gain value, whereas today our money is predominantly paper.

Even though initially that made counterfeiters’ job much easier, over time we have developed some truly fascinating counterfeit detection methods. Experts at Kolibri USA share the story of one of the most commonly used counterfeit detection methods – UV light.

What Is UV Light, Anyway?

You have probably heard about the UV light a lot, and not always in the best light (pardon the pun). However, most of us never need to know what exactly it is and how it works.

The UV light is just like regular light, except the frequency of it is higher than the light we can actually see, similar to how ultrasound has a higher pitch than what we can hear.

Even though we cannot see UV light, we can feel it, because it is absorbed by our skin and in high doses can cause damage to the DNA in our skin cells, causing skin cancer.

How Is UV Used in Counterfeit Money Detection?

Well, the short of it all is that a special kind of ink is used when printing money. This ink shines in a particular way when a UV light is pointed at it.

This UV light can come from a complex thing such as a money counter and counterfeit detector machine, or from something as simple as a UV LED diode.

However, UV sensitive ink can be expensive and complicated to make, so governments and money mints have come up with a compromise – only certain parts of the bill are marked with this special ink, whereas other parts of the bill may be used for other types of counterfeit protection.

What Is in the Ink?

In order to shine when exposed to UV light, the ink needs to contain some chemicals which aren’t usually used in inks.

When it comes to the United States and their UV light counterfeit protection, they opted for a compound with phosphorus. Naturally, due to security reasons, the exact composition of the ink is a well-guarded secret.

One of the biggest benefits of using phosphorus is that in normal conditions, the ink will look no different than regular ink. However, when exposed to a direct and focused beam of UV light, it will begin to shine.

Is This Technique Specific to Counterfeit Money Protection?

Using UV light as a protection method is by no means limited to just money.

In fact, governments love using UV light to protect important documents. Vital documents like passports and social security cards are also protected by this method, apart from other types of protection.

Some other institutions also use their version of this protection. Banks have it on credit cards and travelers’ checks and casinos use it to mark their chips to ensure there is no cheating.

Is It Safe?

In terms of health risks, there is no risk when using a UV light to check whether a bill is counterfeit or not. The strength of the UV light is insignificant, especially when compared to commercially available tanning beds which also use UV lights.

When it comes to security, UV light is not the safest method of protecting against counterfeiting, but it is fairly effective thanks to it being relatively inexpensive and ubiquitous. UV light counterfeit detection is best used in conjunction with some other method like magnetic ink or infrared light detection.