Cabot's Security Materials are used in many security printing applications, and are often incorporated into security inks that are printed onto documents. Printing methods include intaglio, offset, flexography, gravure, screen printing, and inkjet.
Bank notes are the most common application of security printing. Bank notes are produced using a mix of intaglio printing, offset printing, screen printing and letterpress. Security inks used in bank notes range from simple colored inks to overt inks like Optically Variable Inks (OVItm) and covert inks.
The covert inks include phosphor taggants, magnetic and similar invisible markers that are used by governments and banks to authenticate bank notes. Security inks are also used in tax stamps, and identification documents like birth records, passports and visas. Brand packaging also uses security inks to improve security. In addition to traditional printing methods like offset and gravure, ink-jettable security inks are also used.
Cabot produces its unique security materials with proprietary spray conversion processes that produce highly uniform particles. primarily used for covert taggants. Covert taggants are particle or liquid additives that are added to inks, paper, films and other materials. These taggants are typically rare, hard-to-replicate materials that can only be seen in the ink or printed document with a special reader. These readers can be handheld, integrated into other equipment like ATMs and bank note sorters, or they can be special stand-alone devices. These detectors will look for X-rays, electromagnetic spectrum, Raman spectrum, color, magnetism, and other optical effects.
In order to be reliably detected, taggants must be very consistent in their performance and easy to print. Cabot's spray conversion processes result in spherical particles, and the components of the particles are very homogeneously distributed. Because Cabot's particles are small and spherical they can easily be formulated into security inks (see figures 1 and 2). These particles have advantages over other security materials in printing applications because:
- Cabot's particles are highly reproducible, so ink characteristics and performance are very consistent
- Spherical particles are less abrasive to printing equipment
- Our powders create better dispersions which leads to better homogeneity in prints
- Small particle size distribution allows for stable ink formulations (less settling)