Time was when high-quality paper and ink were enough to prove that an official document such as an insurance policy, birth certificate or coupon really was official. Not anymore. Nowadays, digital printers, scanners and image-editing software make it easy for just about anyone to alter or reproduce a basic document right at home, and they make it harder to tell the legitimate documents from the fakes.
But a new technology, announced by Xerox Corporation, could change that. Three scientists at the company's research laboratories in Webster, N.Y., have discovered a way to use an ordinary xerographic printer to insert hologram-like images in common documents. Xerox researchers believe that their new patent-pending Glossmark™ technology could be used to help people identify authentic documents. It could also have novel printing applications - in greeting cards or advertising specialties or for special artistic effects.
Information embedded in a Glossmark print - for example, a seal or a date and time - catches the light when it is tilted and can be seen as an additional and separate image. But the embedded information cannot be reproduced on a conventional copier or scanner. Glossmark technology has two advantages over holograms and other laminates that are used to create similar effects: the Glossmark process does not require any additional printing steps or incremental costs, and it accommodates variable information, like a name, a time-stamp or a code.
It was serendipity - and proximity -- that led to the discovery. Uneven glossy patches, called "differential gloss," are typically considered a defect on a print. Chu-heng Liu, who works at Xerox's Wilson Center for Research and Technology, was struggling with the problem of overcoming differential gloss. He discussed it with his wife, Beilei Xu, and her co-worker, Shen-ge Wang. They both worked in an adjacent laboratory, which studies ways to improve the quality of digital printing systems.
Suddenly the trio realized the problem could be an opportunity. Could they make differential gloss appear on purpose-- and embed images in documents? Experimenting with the concept, they developed software and a special combination of halftones, toner, paper and fusing that would distribute different levels of gloss on the page. The result looked almost like a hologram, but could be produced on an office or high-end production printer.
"Improved printing technologies have made it much easier to counterfeit documents," said Shen-ge Wang, a principal scientist in the Xerox laboratories. "Glossmark prints offer a promising deterrent. Because the differential gloss cannot be reproduced in a second-generation copy, it is a secure technology. It could be used to put authenticating marks on high-value items, like tickets, and on ID cards and other valuable documents. But it can also produce printed materials that are amusing and fun."
Xerox scientists are developing the Glossmark technology to work on a range of printing devices and with a variety of media, as well as creating associated applications to design and print Glossmark images. Xerox is commercializing this technology for use in its products and working with business partners to develop specific market applications. For more information, visit www.xerox.com/innovation.
