Banknotes worldwide have several security measures to prevent counterfeiting and ensure their authenticity. Here are some of the common security measures used.
A watermark is an image or pattern incorporated into the banknote paper during the manufacturing process, and it can be seen when held up to the light.
A security thread is a thin strip embedded in the banknote paper. It can be seen when held up to the light and often has text or images that can only be seen under UV light.
Holograms are images that change colour or shape when viewed from different angles. They are often used on the plastic windows of banknotes.
Intaglio printing is a printing technique that produces raised ink on the banknote’s surface, and this technique is difficult to replicate and gives the banknote a unique texture.
Microprinting involves printing tiny text or images that are difficult to replicate. They are often used in the background of the banknote and can only be seen under a magnifying glass.
UV features are images or text only visible under UV light, often used on the front and back of the banknote.
IR features are similar to UV features, but the IR can only be viewed under Infra Red light.
Each banknote has a unique serial number that helps identify it. These numbers are often printed in a specific font or location and can be checked against a database of valid serial numbers.
Some countries use polymer banknotes made of plastic material, which are more durable and difficult to counterfeit. The UK is currently introducing polymer and phasing out paper banknotes.
These are just some of the security measures used in banknotes worldwide. Each country may have unique security features to protect its currency, some of which are still unknown. There are levels of security, some of which are obvious, like serial numbers to IR ink, that are only discovered later. Some security measures are never found and only discovered after being taken out of circulation—the different security levels help protect the integrity and prevent counterfeiting for longer.