Erasable Paper

Xerox's research arm Monday showcased its latest innovations, including erasable paper.
Scientists demonstrated paper that can be reused after printed text automatically deletes itself from the paper's surface within 24 hours. Instead of trashing or recycling after one use, a single piece of paper can be used a second time, and reused up to 100 times, said Eric Shrader, area manager at PARC.
Predictions that paper would disappear in the 1970s in favor of electronic documents was false, Shrader said. As the number of electronic documents produced increases, about two to five pages are printed in the office for daily use, like e-mail messages and Web pages, which are discarded or recycled after being read. Reusable paper reduces that waste and is environmentally safe, and reuse also helps reduce overall printing and paper costs, Shrader said.
The paper contains specially-coded molecules that create a print after being exposed to ultraviolet light emitted from a thin bar in a printer. The molecule readjusts itself within 24 hours to its original form to delete the print, or heat can readjust the molecule instantly. The molecule was developed by Xerox.
The ultraviolet bar itself is very small, so it can be used in mobile printers, Shrader said. The technology could also be useful for network printing.
For now, the technology prints effectively only in black and white. Although good for everyday prints, ink remains a better option for high-quality prints. Shrader couldn't project when reusable paper or UV printers would reach consumers.
http://www.pcworld.com/businesscenter/article/145254/xerox_showcases_erasable_paper_smart_documents.html