Invisible Barcodes Help Prevent Counterfeit Products
The evolution of barcodes over the decades has largely been in the direction of making them easier to read. But sometimes there are reasons to make codes invisible, or “covert”. This can be for aesthetic, brand authentication, security, or supply chain tracking purposes. It is usually accomplished through the use of inks that fluoresce when exposed to ultraviolet (UV) or infrared (IR) light, which are only visible to the human eye when a UV light source is present.
Uses of covert codes
Counterfeit products are a problem in many industries including pharmaceuticals, cosmetics, luxury goods, tobacco, and alcohol. The consequences of fake products and parts can range from lost revenue to parts that break or malfunction, putting users at risk and leading to litigation. Batch and lot control data in invisible matrix codes can serve as a hard-to-counterfeit sign of authenticity.
2D Data Matrix codes can be unsightly and interfere with high-end package design. Small packaging with many required languages can leave little available real estate for codes. Covert codes do not interfere with visible package design.
Certain types of barcodes contain information that should remain linked to one particular item, such as a time card or other individual record. Covertly printed Data Matrix codes cannot be duplicated by commonly available methods, such as copy machines.
And, if necessary, such invisible markings can be applied to multiple locations on the packaging, making it both easy for the scanner to read the code, no matter the orientation of the package.
Covert Data Matrix codes can contain quality assurance (QA) results, serial numbers, warning labels, supply chain tracking information, and many other types of information. And if there is a recall or product issue, the code can be scanned to verify that it complies with standards or requirements.
Inks and printing methods
Various manufacturers have produced a wide range of inks that fluoresce in a variety of colors in either UV or IR light. UV is more common, and there is a wider range of inks available . While most inks fluoresce in response to a wide range of UV frequencies, specialized inks can be produced that fluoresce only in a narrow band, for added security.
Other than being invisible to the naked eye, these inks behave just like other printing ink, and can be applied by inkjet, thermal transfer, and other conventional printing methods, not requiring any specialized equipment.
Reading covert barcodes
1D barcodes are not well suited for covert printing. The intensity of the fluorescence can vary unpredictably and be uneven from one part of the barcode to another. 2D Data Matrix codes are easier to work with since they take up a smaller region and have more robust error correction features.
While printing the code does not take any additional technology, reading the barcode requires a specialized device. It needs to provide illumination at the required range of UV or IR frequencies and decode the resulting code under a wide range of conditions. A modular mobile terminal that can turn a smartphone into a covert barcode reader is a good option. It uses a UV lighting module and lens filter to illuminate and quickly decipher the code using high performance decoding algorithms. To learn more, download the MX-1502 UV datasheet.