One of the neatest security features on banknotes is the Ultraviolet, or UV, properties that many banknotes have. The ink used is virtually invisible to the eye unless viewed with a black-light. Under the particular wavelength of the black-light, around about 365 nanometers, you can find an area of banknote collecting that many collectors are either unaware of, or have yet to delve into.
To see these images, one needn’t purchase any expensive equipment. I bought a black-light for five US Dollars at a shop selling party supplies and it works very well. I bought a second one at Wal-Mart for about 10 US Dollars, and though it isn’t perfect, I use them both and they illuminate fairly well.
The oldest banknote with UV properties that I am aware of is from Bohemia and Moravia dated 1940. The oldest one I have in my collection is a Czechoslovakian 20 Korun from 1949. While most of the banknotes have a green luminescence to them, there are some that have a red or orange glow instead. The modern US Banknotes have UV Properties associated with the security threads that are embedded into the papers. Under transmitted UV Light, the $5 glows blue, the $10 is orange, the $20 is green, the $50 is yellow and the $100 is red. There is no color associated with the $1 or $2 banknotes as these have no security thread at this time.
The images are extremely varied, ranging from glowing serial numbers, fluorescent fibers or dots to having the whole image glow. Most often though one will see a basic pattern of the denomination, or the country’s arms stamped onto the banknote. Every once in a while though, you will find an image that is totally unexpected.
Below are a set of poor photos from my collection. Photographing most banknotes with UV Properties is a bit tricky, and I haven’t got the technique down quite yet. But as you can see, there is a lot more than initially meets the eye.