Xerox goes green with rewritable paper

Xerox Corp. is working on a green technique that's as plain as the stack of papers on your desk. Scientists at Xerox can make the print on documents appear -- then disappear in time, allowing paper to be reused. The goal is to produce an erasable paper that costs two to three times the price of regular paper but can be used hundreds of times. 

Using a molecular compound similar to the one on tinted eyeglasses, which darken or lighten depending on the amount of ultraviolet (UV) light in the environment, Xerox labs have developed paper that changes color when exposed to UV light. Unlike tinted glasses, however, which change color instantly upon walking outside or into a building, the print on Xerox's paper fades gradually over 16 to 24 hours, or it can be erased instantly by heating the paper.

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Smith's center, which focuses on toners, inks, paper, photo receptors and other materials, teamed up with the Xerox imaging labs in Palo Alto, Calif., to develop the technique. The prototype printer does not use toner or ink, but paper that is coated with photochrome molecules and a light bar with a specific wavelength of light as the writing tool.

It was "quite a complex job," Smith said, drawing on the expertise of the Canadian center's 150 people, including 45 PhD.s. However, the rewritable paper project did not start in the labs, Smith said, but in the office, observing how Xerox customers use paper and rifling through their recycling bins.

"It was kind of intriguing to see what was in the receptacles at the end of the day -- calendars, emails, and always in black and white," Smith said. "Color they keep; they see it as more valuable."

The feel of paper

Predictions of the "paperless office" started in the 1980s, with the rise of personal computers. But paper consumption soared through the 1990s, in part because of the explosion in electronic information that could be printed from the Internet. Office workers store information digitally on the computer to be sure, Smith said, and say they like having less paper in the office. But they continue to print out documents.

"People like the feel of paper. It's light. You can take it to a meeting and don't have to carry your BlackBerry with you," Smith said. The average office worker prints out 10,000 pages a year according to research from the Lawrence Berkeley National Laboratory.

Smith's team also discovered that if people have a printout of a document at their desks -- and know they have a paper copy -- they will often print the document again when they need it rather than hunt for it on the desktop. "Things like that made us really look at how long the image lasted on the paper," Smith said.

Office documents have a short lifespan, said Steve Hoover, vice present of Xerox Research Center Webster, who used an LED pen and a hot plate to demo the rewritable paper last month in Las Vegas at Gartner Inc.'s conference on emerging trends. About 75% of office documents are thrown out in a week's time; 50% within a day, Xerox estimates.

During the past decade, Xerox has tripled the efficiency of its printers and copiers, Hoover said. Since the energy to produce a sheet of paper is 20 times the energy used to print on it, reusable "could have a significant impact on the environment," Hoover said, offering no predictions on when the technology will be ready for marketing.

Xerox's Smith said he sees erasable paper as a transition between paper and electronic paper, which Xerox is also working on. "This is kind of sitting in the middle" he said. "People just really like printing things out, but I think they are becoming conscious about how many pages they print."

Gartner analyst Jackie Fenn, who specializes in emerging technologies at the Stamford, Conn.-based research firm, said erasable paper has practical appeal -- the jokes about disappearing contracts notwithstanding. "People are looking to lower costs wherever they can. And then there is the major green IT theme," said Fenn, who was in Las Vegas for the Xerox demonstration.