Colorants for Security Printing
Fluorescent Dyes and Luminescent Pigments are widely used in Security Applications
Considerable research over the last decade or more on the study of fluorescence has bore fruits in the form of development of new fluorescent dyes. These security dyes are now applied increasingly in the very sensitive area of security printing. The fluorescent dyes are providing ways to create and apply effectively controlled "signatures". The USP of these dyes are that they are customized and are printed as patches on different kinds of surfaces. Each of them has a signature element that is able to identify the patch as authentic. As the different dye formulas are able to vary their fluorescence characteristics in various repeatable ways, as a result unique signatures can be achieved. A very popular Example of a dye that is used in security printing is that of Coumarin 1.
These days a new range of luminescent has been developed that are either excited by UV or IR and applied in security printing applications. Here a few specific uses of the luminescent pigments in the security printing is discussed: Brand Protection and Security of Products-
In applications that involves product security, Luminescent pigments are used in making tamper evident seals for pharmaceuticals and other products. When it comes to brand protection, luminescent pigments and fluorescent dyes are used for proprietary invisible security marks and features which gets printed on products, packaging and labels. Security Printing and prevention of counterfeiting-
Security marks and features that are not visible under normal light are made with Luminescent pigments. They cannot be duplicated even by the ultra sophisticated photocopiers. While they can be easily verified using a very simple Ultra violet light or a luminescence sensor. That is the reason for security printing of stamps, checks, credit cards, licenses etc. are done with Luminescent pigments. Property Identification and Prevention of loss-
As the invisible security marks created by luminescent dyes are not visible under normal, do not deface the property and cannot be removed they are an ideal forensic tool.
Key Features of Fluorescent Dyes
- Minute changes made in the dye formula has the capacity to change the fluorescence characteristics that can noticeable, and measurable as well.
- The Fluorescent Dyes are produced and subsequently modified during manufacture in an unique manner so that only one single particular image will produce the anticipated signature characteristics. Thus making duplicacy very difficult.
- The Fluorescent Dyes have been developed to make them compatible with conventional inkjet printers. This capability has resulted in digital encoding of uniquely identifiable overt or covert marks. It is changed periodically thus making counterfeiting a very short term value or virtually a futile effort.