As brands and governments fight on a daily basis to protect themselves from counterfeiting and forgery,two terms are commonly used are COVERT and OVERT.
As you begin to research using security printing to secure your product or documents, you will hear a lot of terms being tossed around.These are similar words with opposite meanings.
The dictionary lists Covert as: ”concealed; secret; disguised.” In simple terms anything that is not seen by the naked eye is listed as Covert.
An example of a covert image would be one printed with invisible UV inks and fluoresce under UV light.
The example in this picture is a security label with an image which is not visible to the naked eye but visible UV Light.
Another good example is a Rastered image that is normally hidden to the naked eye but viewable under a Decoding lens. See image below of a Packaging Carton with a hidden image.
Overt on the other hand is listed as “open to view or knowledge; not concealed or secret:”
The oldest overt feature on a secure document is a Watermark. See image below of a banknote with watermark of Mahatma Gandhi.
Another Overt feature is a hologram.This picture is of a hologram on a Credit Card which quickly allows an inspector to glance at the card and verify the Hologram.
Advantages of Overt
- Instant Verification
- Predictable, repeatable behavior.
- Secure alone or as a layer
- Angle of light response
- Persistent or disappearing
- No additional device is needed for authentication.
Advantages of Covert:
- Higher Level of Security as not open to view.
- Location of the feature on a document or Package can be concealed.
- In many cases only covert features are admissible in a court of law as evidence
Conclusion: It is only a combination of Overt and Covert features together that can provide a reasonably secure document or product and no single feature in itself is usually sufficient. Brands must innovate to make a correct mixture of these features and continue to modify the combination to thwart the efforts of the counterfeiter.