History of Security Inks Usage
The history of security inks is far more ancient than one might imagine, with the first mention of an invisible ink being used as a secret means of war time coming from the Greek writer Aeneas Tactcus in the 4th century BC. Philo of Byzantium, another Greek writer from antiquity, described an invisible ink comprising a reagent as far back as the 4th century BC. The Arabs started using lemons as organic inks in the 7th century AD as did the Europeans in the 16th century.
Alum invisible ink 1600s
Italian scholar Giovanni Battista della Porta gets the credit of creating the first sympathetic ink by using alum and vinegar. He, in fact, wrote the first book, Magia Naturalis, on invisible inks and secret writing back in 1558-59. That really set in motion the whole process of using secret ink for security and covert operations. A secret formula somewhat akin to gall ink, “oak gall ink” was created by John Jay during the American Revolution, which was deployed by George Washington and the Culper Spy ring to great effect.
Lemon juice was put to use by the four German Lemon Juice Spies5, as well as the English baker John Hanh during World War I. In the Second World War too, neutral and acidic solutions of phenolphthalein were used as invisible ink. This colorless solution would turn pink on the application of alkaline substances like ammonia and bicarbonate soda.
The history of security inks is as fascinating, as it is ancient with many twists and turns to its tale, befitting a grand historical literary masterpiece. That security inks continue to be used as a principal method of fighting counterfeiting in the digital age is enough testimony to its continuing importance in today’s times.
Science Behind Security Ink
While most people equate security ink with invisible ink, the fact of the matter is that there are a number of other types of security inks as well. Security ink, for instance, may be of the photosensitive type that while being visible to the human eye is either not detectable under a UV lens or visible in a different color.
Invisible Ink Demystified
Ink by itself need not have a color. The dyes and pigments that are put into ink are what makes it visible to the human eye. If you change the composition of these dyes and pigments in a certain manner, they can be rendered invisible to the human eye. This sees useful applications in a variety of security related applications.
It is important to know that taggants are microscopic particles added to ink that react when near a reader, verifier, or scanner using a UV or infrared light of a specific wavelength. There are heat and chemical activated inks too, but these don’t see much practical use, outside of science experiments.
Where the need for security is not very stringent like in the case of a movie ticket, the security ink in use can be scanned by a diverse range of wavelength and scanning devices. In the case of a higher level of scrutiny, the taggants in question will only react under a light that is customized for the purpose.
What goes into creating security inks?
A number of elements go into the making of security inks. These include the substrate (the material that the ink will be printed on), the number of times the printed items will be used, the kind of visible properties the ink in question should have, the detection mechanism to be used, the security level required and the kind of printing to be done.
While security inks have been around for a very long time, indeed the proliferation of inkjet printing technology has added a whole new dimension to it. It has vastly reduced the set up time required for printing and has therefore made it possible to customize security ink to a single unit level. This greatly reduces printing downtime while adding to production capabilities. This has a direct bearing on consumers as manufacturers are better able to protect them against fraud and counterfeiting.
Going forward one can expect to see scientists think of even more novel ways of leveraging the power of security inks to give us an even more enhanced level of security for the products and services used by us. For instance, security printing can already be carried out on non-porous substrates like plastic and polymers enabling documents and bank notes to resist both tampering attempts and the effects of abrasion.
Future trends in Security Printing are getting on the way with the new nanoprint technologies, printed electronics and revolutionary inventions in digital printing. These and many more are to become the new security printed features in order to protect the public from illegal activities and bring a more safe and secure future of printed documents. What one needs to understand about security inks is the fact that these come in certain distinct types, some of which are listed below:
- Invisible
- Biometric
- Thermochromic
- Fluorescent
- Magnetic
- Optically variable
- Infrared
- Reactive
- Erasable
At a time when counterfeiters are using increasingly more sophisticated techniques to infiltrate supply chains and pass off fake products as the real thing, it is the ancient technique of security inks, albeit in its modern versions that are stepping up to the plate to save the day.
In an era where data and information are critical to the success of any business or organization and where losing the competitive edge due to counterfeiting or pilferage can be crucial, security inks are usually the first line of defence. Going forward, the advances in security inks technology will ensure that critical information stays secure and the integrity of goods and services is maintained on behalf of all manner of business and organizations.
No matter how clever and ingenious the efforts of counterfeiters might be, the security inks industry will always manage to forestall any nefarious moves that they might be contemplating.
Security Ink Technologies
The world has come a long way since the days of using lemon juice as security ink and these days there is a diverse range of security ink technologies to choose from. The challenges faced by industries, organizations, and individuals on account of counterfeiters and cybercriminals are immense necessitating the most stringent measures to combat them. Let’s take a look at the myriad types of security inks used as anti-counterfeiting technologies that can be deployed in this regard:
Biometric Taggants
These kinds of inks have DNA taggants in them that have the ability to react to reading solvents or can be read with the help of machines. This allows for the authentication of both products and documents. Biometric taggants are in effect a covert security feature that require technical assistance in validating the authenticity of products.
Erasable Ink
Erasable ink is generally seen in the background of certain documents and comes into play when somebody tries to erase information, by simply getting rubbed off. These are useful in protecting checks and certificates. These are best suited for dry and wet offset printing and are not suitable for laser printing.
Coin Reactive Ink
White or transparent images printed with the help of this ink reveal themselves when rubbed with the edge of a coin. This is a simple and straightforward method of validating the authenticity of a document without having to use any special equipment. What makes this additional secure is the fact that it can neither be copied nor scanned. Coin reactive ink sees use in wet and dry offset as well as flexographic printing.
Bleeding Ink
It is so called because it prints in black, but turns red when exposed to an aqueous solution. This helps one authenticate documents without having to use any special agents. All one needs to do is to run a wet finger along the printed matter and the red stain begins to form. This kind of ink can only be deployed in dry offset printing.
UV Invisible Fluorescent Ink
This type of ink is either transparent white or colorless, detectable only under ultraviolet light. This comes in handy in verifying documents with the help of UV light. UV fluorescent inks cannot be copied or scanned and are suitable for use in dry offset, flexographic and gravure printing.
Invisible UV Fluorescent Ink When Exposed to UV Light Illustration
Thermochromic Ink
These are inks marked by their ability to react to changes in temperature in that they are visible at certain temperatures and invisible at other temperatures. Application of a higher temperature would make the ink disappear and vice versa. Different inks have different temperature sensitivities. Typically, these could be 15 degrees, 31 degrees and 45 degrees celsius. In hot places like the tropical regions, it might make better sense to deploy a thermochromic ink of higher temperature sensitivity.
Then there are some thermochromic inks that change their state from invisible to visible, lending them to use in labeling frozen food packaging where the appearance of color indicates a thawing of food.
Color change effect in thermochromic ink as temperature changes
Fugitive Ink
This type of ink reveals any form of alteration with ink or an aqueous solution in the form of smudges in the printed area. This is typically noticeable in checks, where any attempts and altering the contents will reveal the smudges.
Chemical Reactive Inks
The ability of this type of ink to react to solvents or chemicals will cause this ink to run, smudge, form a stain or change color. This helps detect any attempts at tampering of any document. These inks can be deployed for wet or dry offset printing.
Optically Variable Ink
Also known as OVI, the specialty of this ink is that it contains very tiny flakes of metallic film which invests it with a peculiar optical property. When viewed from different angles the color of the ink changes accordingly. Owing to the expensive nature of this ink, it is printed on a very small area, usually on currency notes or visas.
Magnetic Ink
This type of ink contains tiny iron oxide magnetic flakes that enable printed numbers to be read by machine. As one might imagine, these inks are largely used for serialization as well as numbering. It sees widespread use in the printing of checks, in the shape of the MICR numbering part at the very bottom of a leaf of check.
Penetrating or Indelible Ink
This special kind of ink that comprises a red dye has the ability to permeate into the fibers of the printing paper and become visible right to the back of a document. This keeps the numbering on official documents safe from any tampering effects on account of the fact that any attempt at scraping a number off will leave a red stain behind.
Pen Reactive Ink
This is a transparent ink that becomes apparent on application of pressure by a special felt pen tip. This can be used to both authenticate a document and cancel one that has outlived its utility. These inks are used in the case of dry offset printing.
Secondary Fluorescing Ink
It is similar to fluorescing ink with the only difference that it will not glow or become visible under a UV light if no attempts at alteration have been made. This is a backup measure and often accompanies a primary fluorescing ink to comprehensively detect an alteration attempt.
Photochromic Ink
Colored or colorless photochromic ink changes color when exposed to UV light. On taking the UV light away from it, the ink will regain its original color. A scanned or copied version of this kind of ink will not possess these properties. Documents printed with photochromic ink can easily be verified with the help of UV light or even sunlight. This ink can be used in dry, wet and flexographic printing.
Color change effect of photochromic ink
Visible Infrared Ink
These come in both readable and disappearing ink types. Both types of inks will look the same once printed, but one type will be readable under infrared light while the other type will become invisible. A barcode printed with both kinds of inks will be a fine security feature in that if a counterfeiter tries to replicate the printed barcode its entire contents will show up under infrared light. This will expose the fake nature of the bar code in question, as only the bard code printed with readable infrared ink should have shown up.
Metameric Inks
These inks are based on the principle of metamerism under which two colors are combined to make the resultant look different under different lighting conditions. This can help show up features (like a number appearing when placed under a red filter) that are not visible under other conditions. As can be imagined these inks can be very useful in imparting security to packaging or documents.
Adhesion Promotion Varnish
This ink is only visible under an ultraviolet light. Its speciality is that it not only promotes toner adhesion to the base paper, but also changes color in case someone tries to get rid of the toner by rubbing it off.
The thing about security inks is that they come in a large number of types allowing them to be used in a large number of applications across industries and organizations. Security inks help secure manufactured products, documents, and consumers against forgers, fraudsters and counterfeiters. Security inks can be used both overtly and covertly to secure diverse kinds of packaging, labels and closures. These help protect both brands and consumers with the help of an extensive range of solutions that can be easily integrated in an existing ecosystem of suppliers and associates. Not just that, most modern security inks can be customized by way of many colors and coatings with the added advantage of being compatible with almost all conventional and digital printers and applicable on all kinds of substrates.
Going forward, one can expect ever new technological innovations to take security inks to even higher levels of performance. This is just as well, because modern day counterfeiters and forgers are also extremely tech savvy, requiring one to stay ever vigilant. Security inks might be as old as antiquity, but they still remain relevant in the current digital age.
As long as scientists and technicians can continue to innovate and improve security inks, one can expect this tool to effectively solve the challenge of counterfeiting. No matter how smart and adept criminals might be, they will be found wanting by the slew of security ink solutions ready to confront them. Security inks will continue to provide out of the top drawer security solutions well into the 21st century.
Security Ink Applications
The need for secrecy, privacy and confidentiality as well as the desire to protect product and document integrity is served by security inks of various kinds. Let’s take a look at the premier application of security inks:
Bank Notes
Security inks perform very vital functions in ensuring the security of bank notes. They do this with the help of a number of special features that may be in the shape of high quality intaglio inks, optical effect links, luminescent inks, as also a diverse range of machine-readable solutions customized to meet the challenges arising from automated handling of bank notes. Post-printing varnishes protect bank notes from soiling, tearing, defacement and other forms of damage and prolong their life.
Staining inks on the other hand help people detect stolen bank notes. What adds to their efficiency is the fact that these are completely indelible.
US $20 Bill Showing Stripe Under UV Light
Security Ink in Textile – Visualized Security Tag Using IR-cam and IR-light (DITF)
Textiles
Digitally printed invisible IR active security tags embedded on cloth or textile that can be decoded with the help of IR light and IR camera make use of security marking that is invisible to the human eye. The kind of transparent ink used for this process can be used equally well with paper, leather crust, kevlar, PVC and other materials. The fact that these inks resistant to dry and wet rubbing makes them all the more useful for protecting textile products.
Packaging
Invisible ink detectable only by UV sensors can help safeguard packaged products against pilferage and counterfeiting by helping validate a product package. Invisible markings also help in the packing stage where a spool of packaging film can be marked invisibly to enable cutting it in the dimensions required in an aesthetic manner.
Official Documents
Security inks perform a stellar role in imparting a high level of security to official government documents like passports, birth certificates, visas, passports, and driving licenses. There is a wide range of security inks that caters specifically to these requirements. These include intaglio, flexography, silk screen, gravure, offset letterpress and inkjet printing.
Security inks and coatings contain covert and forensic taggants that provide fool-proof protection against counterfeiting, on account of their complex formulation. What’s more, forensic features can be added to help furnish legal evidence.
Artwork made using security ink in Canadian Passport
Labels
High-security labels are a highly economical and efficient way of fighting counterfeiting. These come equipped with covert features like micro-printing and of course invisible ink containing taggants as well as color changing inks. All of these combine to make the packaging as unique as possible. A broad range of security inks used to make customized label stickers empower both consumers and inspectors to get a handle on counterfeiting attempts, warranty fraud, return fraud, as well as parallel trading.
Pharmaceuticals
Counterfeit medicines are a huge global problem with catastrophic consequences for the healthcare sector. Not only do pharmaceutical manufacturers stand to lose money, but also their fair name on account of this. Worse, it wreaks havoc with people’s health.
A lot of research is going on about using security inks to tackle this menace. In this regard, the fluorescent compounds fluorescein and tryptophan have been formulated into security inks that one can directly print onto medicines. These can be effectively used for authentication purposes
Wines and Spirits
The wines and spirits industry too is not immune to counterfeiting and its ensuing ill effects on profitability and brand reputation. There are multiple ways in which security ink can be used on the label of a wine bottle to protect it against counterfeiting. For instance, one could witness a color shift in the label when viewed from different angles. Then there are semi-covert properties in the security features that are activated with the help of light polarization filters.
One can also use an invisible fluorescent ink that glows in ultraviolet light. That apart, there are covert security features incorporated onto the label that are invisible to the human eye and can only be read by machine.
Handbags and Cosmetics
There are fluorescent inks that can help consumers detect counterfeit products like fake bags and cosmetics by simply photographing the product in question with their phone camera. These inks that can easily be printed with an inkjet printer are invisible to the human eye, but can be viewed under ultraviolet light. The inks can be stamped as a QR code or a barcode on the product in question so as to enable one to easily validate their authenticity.
This can be used not just in the case of handbags and cosmetics, but in a range of other branded products with a high susceptibility to counterfeiting.
Concert, Sports and Lottery Tickets
Concert, sports and lottery tickets printers have taken to leveraging the power of security inks to protect against counterfeiting. One could do this by printing a hologram on the back of every ticket along the perforation. Tamper-resistant holograms ensure that the tickets are not compromised by way of counterfeiting
Another way of providing security to tickets is by providing them with glossmarks. These faint dotted lines become visible on moving the ticket One can also use UV security paper to print the ticket and this will ensure that it does not get copied.
The invisible ink in the UV paper can be seen under a backlight thereby enabling one to validate their authenticity. On could also use heat sensitive security paper to print the ticket. This possesses the unique ability to change color when exposed to heat, something that can be triggered by simply holding the ticket in one’s hand.
Thus, one can see that the application for security inks are practically endless. Even though security inks have been around for thousands of years, their wide range and adaptability to ever changing technology makes them never go out of fashion. In fact, these have evolved to become the most sophisticated security tools in the security arsenal of businesses, organizations, consumers and individuals. Going forward one can expect security inks to continue ruling the roost in the pressing fight against the counterfeit industry.
Matrix-Mark™ Taggants: Enabling Next-Generation Security Inks
Invisible marks printed using inkjet ink containing MatriX-Mark™ Taggants
Transforming Ordinary Inks to Next-Gen Security Inks
When an ordinary ink is armed with MatriX-Mark™ Taggants, it will bring the next generation of protection to even the most complex product and document supply chains.
Also known as a tracer element, a taggant is one of the most versatile anti-counterfeiting technologies on the market. Taggants are the physical or chemical markers added to materials for the purpose of identification. A taggant is like a fingerprint—a unique signature of identity which is virtually impossible to duplicate.
These taggants or chemical tracers are super-invisible particles (cannot be detected by IR / UV) and can only be detected using dedicated scanners. These inorganic markers also withstand high physical and chemical resistance tests which helps in long-term authentication.
These taggants don’t alter the appearance, color, or chemical makeup of the material they are mixed with (e.g. ordinary ink or security inks). Matrix-Mark™ Taggant possesses strong chemical characteristics that make it a trusted solution to fight product counterfeiting.
Versatile Delivery Options
Owing to the material characteristics of MatriX-Mark™ taggants, they can easily be added to any ink color and type. The addition of these taggants does not impact the security ink’s optical, chemical, and physical performance and related characteristics.
MatriX-Mark™ Taggants are versatile since they can be used with different printing methods and a vast array of colors. These taggant versions can be easily supplied within coatings and inks or without any color (invisible) as well.
- Offset / lithographic ink
- Flexographic ink
- Silk screen ink
- Rotogravure ink
- Intaglio ink
- Inkjet ink
- Laser Toner
- Thermal transfer ribbon
- Plastic pellets for injection molding
- Clear coating
These taggants have the following properties:
- For all printing technologies: Offset, rotogravure, flexo, screen, intaglio, inkjet, laser, TTP, etc.
- Inorganic: No performance impact by age or exposure to strong UV radiation
- Tough: Sustained pressure even in intaglio printing process
- Chemical resistant: Withstood chemical resistant tests even for banknote use
- Temperature resistant: Melting point above 1000°C
- Small size: 500 nm to 5 micrometer (depending on application)– difficult to detect
- Complex formulation: Virtually impossible to re-engineer
- Involves proprietary well researched methods of forensic detection: Every taggant comes with a unique forensic feature that enables the trace element to be used as evidence in the court of law.
Matrix-Mark™ Taggant Security Features
Sophisticated covert feature (Level 3)
Detection principle: Invisible light from emitting device will be converted into another invisible light wavelength. The unique particle characteristics can only be detected with proprietary detection systems. Multiple taggant versions are available.
This is an advanced anti-counterfeit feature as it cannot be detected with ‘simple’ verification tools, e.g. UV light or IR laser pen.
Forensic security feature (Level 4)
During production of the MatriX-Mark™ taggants a unique forensic feature can be added. A nearly infinitive number forensic signatures can be added to provide irrefutable proof of authenticity in court of law, beyond any reasonable doubt.
For detecting MatriX-Mark™ Taggants, handheld devices or in-field single- or multi-taggant detectors and similar inspection systems need to be used.
These specialized detectors and scanners carry out complex analyses before confirming the presence of a taggant version by giving a binary response. Different high-speed and fully automatic detection devices for locating the presence of security taggants in documents or products can also be used.
Taggant detection instruments and sensors
Enhance Product Authenticity and Traceability with MatriX-Mark™ Taggants
The inks with MatriX-Mark™ Taggants have already been successfully used in rotogravure, screen printing, flexo, intaglio, offset, and other printing methods. The high usability of these security taggant versions cements the fact that they can be seamlessly integrated into different products and production processes.
Strengthen product authenticity and traceability with next-generation security inks that are empowered by MatriX-Mark™ taggant technology.