8 Types of Security Inks and Their Applications

There are many types of ink being manufactured today.. Security ink is used for printing on passports, checks, some secure documents, and security labels just to name a few applications. There are several different types of security ink available for these applications that the following will cover.

Security Inks

  1. Biometric – Biometric, as its name implies, contains DNA tags. Special machines are designed that can read the tags, or the tags can be manufactured to react when a particular solvent comes in contact with them. Biometric ink is suited for applications where authentic product verification is necessary. Special methods are used to validate the authenticity of biometric ink printed products.
  2. Reactive – Reactive ink is also referred to as solvent sensitive. This type of ink can detect when there is an attempt to alter the document. An example of reactive ink is found on checks where variable data is printed on them. Watermarks are created with reactive ink.
  3. Optically Variable – Optically variable ink is also known as OVI in industry circles. Tiny flecks of metallic film that changes color when viewed from different angles. It’s somewhat like holograms. OVI ink is extremely expensive and must be printed in heavy weight. It’s used for passports and currency, for example. Color variations can include changing from brown to green then green to brown, or red to purple then purple to red respectively.
  4. Secondary Fluorescing – Fluorescing is an ink that becomes visible when it’s exposed to UV light. Like reactive ink, it’s purpose to detect alterations and tampering on the material upon which it’s used. For instance, the secondary fluorescing ink will look green under UV light, but turns red (the secondary color) if tampering has occurred.
  5. Thermochromic – As the name implies, thermochromic ink is designed to be sensitive to temperature. It will appear or disappear when it’s exposed to different temperatures. While it comes in a variety of temperature sensitivities, but the most common are 15.the most common are 15.31, and 45 degrees Celsius. Before using this industrial ink, it’s vital to consider the temperature conditions to which it will be exposed from the time of imprinting through its lifecycle.
  6. Invisible – Invisible ink is used to protect documents like checks. This type of ink is designed to be invisible to the naked eye, but visible under ultraviolet light much like fluorescing ink. Black light is the most common light source for making invisible ink visible.
  7. Magnetic – Magnetic ink is used where numerical sequences or serial number security is important. Magnetic ink contains magnetic flakes designed to communicate with electronic readers for document verification. It’s another ink used for checks MICR numbers in the UK. That MICR number holds highly sensitive data like check number, account number, and sort code.
  8. Water-Based Fugitive – Fugitive ink sounds mysterious, but it is designed to react much the same way as reactive ink. When an alteration attempt is made on a document with fugitive ink using any kind of liquid, including water, the ink will run, causing it to smudge and become unreadable. Even your finger with saliva on it will affect the printed background of a check or document with fugitive ink on it.

These are the eight primary types of security ink and how they are used on various documents. The mystery of security and invisible ink is now revealed.