Specialty Inks

By Mike Agosta, Ink World Associate Editor | 09.09.05

Thermochromic and photochromic inks have shown great potential to make important documents safer from counterfeiters and protect the integrity of security institutions.

Security is on the mind of everyone these days, and the ink industry is at the forefront of industries looking to do their part to make the world more secure. Among the newer technologies to come out of the ink industry in the past few years, thermochromic and photochromic inks have shown great potential to make important documents safer from counterfeit and protect the integrity of security institutions.

According to industry insiders, annual sales of thermochromic and photochromic inks hover around the $20 million mark. Considering the overall size of the ink industry itself, this represents a very small portion of sales. These inks are truly a niche market.

The technology to make thermochromic (inks that change color when exposed to heat) and photochromic (inks that change color when exposed to light) inks has been around since the mid 1970s. Initially, according to Bob O’Boyle, director, technology transfer USA, Sun Chemical Corporation, they were introduced for use to a toy company. It wasn’t until after they took off that their use was expanded to other markets.

The unique features of these inks made their possible use in security applications an attractive possibility. “Inks that change color with human touch are impossible to counterfeit and very difficult to acquire,” said Glenn Small, vice president, sales and marketing, Chromatic Technologies, Inc. “These inks make for a very effective security feature.”

According to Mr. O’Boyle, the need for inks that are difficult to counterfeit rose out of the advancements in home printing technology in the past 10 years that allowed the average person to make incredibly high quality copies of documents. “Security inks like this were developed to prevent tampering or counterfeiting,” he said. “The biggest boon to counterfeiters was the digital age of scanners, color printers and color copiers, which made the copying of documents extremely easy. Thermochromic inks cannot be copied by electronic means and, as such, have found use in a wide variety of secure type applications from bank notes to letterhead stationary and everything in between.

Despite the difficulty in copying an ink such as a thermochromic or photochromic, counterfeiters can find ways around such features simply by acquiring these types of inks. As such, other measures are generally taken to prevent the success of counterfeiters. “These inks are used extensively along with other covert and overt security measures,” said Mr. O’Boyle. “Thermochromatics are rarely used today as a single security measure because a determined counterfeiter can buy these types of products on the open market.”

An example of the thermochromic technology available from Chromatic Technologies, Inc. demonstrates its use in determining the proper drinking temperature of a beverage. On the left, the beverage is too warm, but once cooled, a stripe appears (right) indicating the product is in the proper range.
Pat Laden, vice president, Atlantic Printing Ink agreed.

“Photochromatics by themselves are interesting, but not really functional as a security application,” he said. “When you tier three or four different products with it, both covert and overt, it becomes part of a very functional security package for product validation.

“Anyone who can get on the Internet can get samples of photochromic pigmentation, and pretty much get to where you need to be to counterfeit it, depending on their level of expertise,” he continued. “Our specialty is to tier two or three or four different security inks, some overt, like thermochromatics. These you can see and try and duplicate
it, but they might not look for the covert types of applications. They know about some things but don’t notice the others that might be there to help validate identification. It’s a bait and switch type of thing. You want them to see something, but not everything, hoping they’ll miss something that will give them away. ”

According to Mr. Laden, these types of security applications can be used in a variety of situations. “We do cash out tickets for slot machines,” he said. “It used to be that when someone hit the jackpot, the coins would all pour out. But everyone saw this happen and people would attack you, grab your bucket and run out the door. This happened often enough that now they give you a ticket instead when you win.”

These tickets created a different kind of problem, Mr. Laden said. Now, instead of worrying about people stealing from winners, the concern is people stealing from the casino. “People would go home, scan the tickets into computers and print out a bunch of them and take them to the casino,” he said. “The casinos were losing a lot of money, and so they needed a way to validate the real tickets. That can be as simple as putting an invisible stripe on a ticket that turns color when rubbed with a special pen, which is relatively inexpensive. Or it could be a thermochromic application where a logo or the word ‘valid’ appears when the ticket is held over a heat lamp.”

Thermochromic and photochromic inks are also useful in brand and product validation. In another example cited by Mr. Laden, Atlantic Printing ink was recently approached by a maker of automotive parts. According to Mr. Laden, the automaker had issues with counterfeit oil filters produced in the Pacific Rim and bearing the logo of the company that were flooding the markets. Atlantic Printing Ink was able to produce a tiered security system that allowed the company to prove which products were theirs and which were counterfeit.

“Once the company can prove that the fake products aren’t theirs,” said Mr. Laden, “they can go to where the product was purchased and see if, indeed the retailer was buying fake products purposely or real ones.”

The problems with counterfeiting have taken on an even more urgent tone following the attacks of Sept. 11, 2001. The concern over protecting secure areas has opened new doors for security ink applications.

“Because we have a security ink web site,” said Mr. Laden, “after 9/11 we’ve been inundated with new areas of application. The National Transportation and Security Board (NTSB) contacted us and wanted to know about the possibility of very transient inks on identifications for truckers. Because people who work for freight companies often don’t hand in their badges when they leave, there is concern that people could have access to restricted areas where they shouldn’t be. The NTSB wanted ink for the ID badges that would disappear after 30 days.”

Other Areas
In addition to the number of security and identification uses, thermochromic and photochromic inks are exhibiting potential for use in other areas as well.

According to Mr. Small, Chromatic Technologies has developed a hot coffee warning label for mugs that warns a drinker when a drink is too hot. “We have developed a hot coffee warning label that I believe should be on every cup of coffee,” he said. “Because the activation temperature for these inks can be adjusted, the coffee label only warns the consumer when the coffee is above a certain temperature.

He added that beverage companies are using these inks to indicate the ideal drinking temperature for their products.

According to Mr. Laden, the thermochromic technology for beverages first became popular with wine labeling. “The wine labels are the first time in the history of graphic arts where there was a user interactive label,” he said. “It was a user interactive product in the sense that it would say ‘too warm’ or ‘chill again’ or something similar to indicate to the wine drinker when the product was at the correct temperature to drink.

According to Mr. O’Boyle, it is areas like this that exhibit some of the largest growth areas for thermochromatic and photochromatic technologies. “Interactive packaging, to me, seems the largest area for growth,” he said. “Labels or containers sensitive to heat at various levels could be used for safety (too hot), on beverages (cold) to anything else a producer would like to convey to a consumer.”

Mr. O’Boyle also added that he thinks there is future for thermochromatics and photochromatics in the promotional advertising market. “I would think that any time something interactive is called for there would be a use for thermochromatics and photochromatics,” he said. “I have seen promotional t-shirts that, when exposed to sunlight, have graphics that magically appear as an example.”

Mr. Laden agreed, stating, “Unique novelty items like shirts that change color are another potential area.” However, he believes that these types of areas will not come to full fruition until after the security market for these products has matured a bit.

“Once we get over the initial hump, when the country is comfortable with the security applications that are in place now, different types of usage will be found for these products. Right now, it’s mostly security.”

Mr. Laden also cautioned that this type of technology is sensitive, and because of its security applications, it must be protected and kept out of the hands of people who would misuse it. “It’s our responsibility to keep this stuff out of fraudulent hands,” he said. “And when someone doesn’t know what they want to do with it or how to use it, all the bells and whistles must go off. You constantly have to look at that.

The possibilities for thermochromatic and photochromatic inks seem endless. With so many areas of life requiring security these days, those possibilities will only grow. “We’ve seen this technology ratchet up a lot, from simple types of ink systems, to layered types of complex ink systems,” said Mr. Laden. “I’ve not seen the end of it yet. I haven’t seen the top of the hill.”

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