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Just what James Bond ordered - paper on which the writing vanishes
Last updated at 23:07pm on 20.01.07
It sounds like something James Bond's gadget guru 'Q' would come up with - paper you can use time and again because the writing on it disappears.
The 'erasable paper', from which words or images simply fade, can be used up to 100 times and is being hailed as the ultimate in recycling.
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The design will allow secret documents to vanish within days and, more mundanely, reduce to a fraction the paper used in offices.
At home it could mean reusable shopping lists.
Xerox, which is behind the invention, estimates that two of every five pages printed in offices, such as emails, meeting agendas and internet pages, are viewed only once before being thrown away.
The revolutionary new paper is used with a specially designed printer that 'writes' with a light beam instead of ink.
The secret to the process lies in a clear-coloured chemical on the surface of the paper that turns a blue-purple colour when exposed to the beam.
Letters and images traced out by the beam become visible, giving the impression there is ink on the page.
But the blue-purple form of the chemical is unstable and, 16 to 24 hours later, it returns to its original, clear form and the words disappear. The print can also be instantly erased by exposing the pages to heat.
Xerox has developed the paper in collaboration with the Palo Alto Research Center (PARC) in California. In future it may be possible to write on it by hand - using a pen powered by light beam.
PARC manager Eric Shrader said: "There isn't a limit to reusing the paper from a technical point of view - it depends on how careful you are with it. I have used pieces myself 50 or 100 times.
"It could be used for a daily calendar or anything you need to keep for a while but not for ever. Security is definitely an application.
"When you talk to security experts, they like to have a guarantee that after a certain amount of time the image will be gone."
The paper's inventors are also working on a way to make it rapidly blank again without the need for a heat source, by using one type of light to print and another to switch it back to being clear.
Mr Shrader said: "The paper is still being tested in the laboratories and it is several years from being a commercial product."
Xerox says it will cost more than ordinary paper and customers will need to buy a beam-powered printer.
