Inside Print's Laboratory

Print Action, Mar 2005 by Robinson, Jon

Scott Williams is an associate professor of imaging chemistry and physics at Rochester Institute of Technology's School of Print Media. When not teaching classes, he is conducting Ph.D.-enabled research into ink formulations, paper coatings and chemical-like technologies related to the process of print. He is not exactly working with a mixture of soot from pine smoke, lamp oil and the gelatin of donkey skin, as did Chinese philosophers when they invented Indian Ink, but Williams insists ink formulation is still based on a 3,000-year-old methodology - a colourant, vehicle and additives.

"If you really think about what is in the technology, inside the formulas, and if you really let your mind wander, you can come up with some pretty innovative applications," says Williams. In fact, creativity has been sweeping through the ink industry for the last three decades and only now is the world beginning to see exactly how. "It's like cell phones. It's technology that people rely on and use, but they do not understand or realize its pedigree. It is based on taking fundamental concepts in a traditional technology and making advances that bring about new products."

Traditional ink manufacturing, Williams estimates, has generated about two or three patented innovations each year over the past 30 years or so. However, patent development of conductive inks, over those same three decades, account for more than 3,000 registered innovations. "When you talk about the newer processes like security inks or conductive inks, today we are up into the tens - if not hundreds - of patents per year," says Williams. He suggests RFID receives the attention it deserves (see PrintAction, February 2003), but that security applications, specifically micro printing, are often overlooked in the mainstream even as some innovative printing companies are fully embracing it.

Along with the potential applications of micro printing and RFID, Williams also includes energy-curable inks, such as Ultra Violet and Electronic Bean, in this group of technologies that will literally change the way we view the world.

Finding something small

"Micro printing, which I believe was developed in part here at RIT, takes advantage of some differences between [traditional] commercial printing technology and what the digital age can offer," says Williams, suggesting currency and cheques are probably the best-known example of how this technology is applied. The line where a cheque is signed is not a line at all, but very tiny words saying something to the effect of MICROPRINTED TECHNOLOGY or THIS IS LEGAL TENDER DO NOT REPRODUCE.

Cheques are usually printed with a lithographic process that can reach a 10-micron area with 10-micron dots. If such a cheque was photocopied the micro printed text would blur. "The digital technology as it stands today cannot micro print down to that level. The micro print disappears when it has been xerographed. At best a digital printer can only handle about a 30-micron dot." Even if cheques are an old example of micro printing, advances in plate technology, ink and CTP engines are designed to chase after a fine dot and they are reinvigorating this sector.

"You can use micro printing anytime you have a product that has perceived value, requires either protection or some record of its origin, or if you want to transfer information only to those who really need to see it," says Williams.

The talk of nanotechnology once flooded the investment community, until so many venture capitalists fell in the face of a troubled economy, but the long-term prospects in this field certainly stand to enhance the future of micro printing by providing more control over pigments. The pharmaceutical industry, according to Williams, innovated ways to make finer and finer preparations of its drugs, and the pigment industry responded to those methods in kind.

Ink may still be formulated using the basic principles of a 3,000-year-old process, but suddenly the ability to control that basic set has changed. "If you talk about micro printing, it requires that the pigments be of a certain size and shape to have micro detail without it being overwhelmed by the size of the pigment." Williams also points out that nanotechology is of some interest from some paper companies working to embed technology into smart papers. This requires specialized coatings using nano-based technologies.

The direction of all of this technology can be very overwhelming, and this is why much of Williams' research is geared toward making the new frontiers of imaging materials fit into a blind printing process. "If the process printing engineers do their innovations in a forward-thinking way and the ink manufacturers design their conductive ink formulations in a forwardthinking way, the ultimate goal would be having all of that technology essentially blind to the printer. In other words they would be able to print an RFID box as easily as they can using conventional inks and methods."

The ultimate goal for everyone involved in RFID is to use the existing offset printing infrastructure. It is the only way to make the antenna cost effective. Chips, on the other hand, are an entirely different challenge. A faculty member at RIT is in fact dedicated to figuring out how to enable RFID printing using a traditional flexographic 4150 press. The direction of RIT brought Williams back to the school after spending four years working on electronic papers in the corporate world. Now back two years, he is seeing more and more of that corporate world being drawn into the school.