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It could mean the end of paper as we know it - and give e-books a run for their money.

Experts have revealed a new type of paper that can be erased and rewritten without the need for ink.

They say that even in early prototype form, it can be rewritten 20 times without affecting the resolution.

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The new rewritable paper can be erased and written on more than 20 times with no significant loss in contrast or resolution.

It works by using ultraviolet light to photobleach a dye in the paper, except the portions that constitute the text on the paper.  

The new rewritable paper can be erased and written on more than 20 times with no significant loss in contrast or resolution. 

Chemists at the University of California, Riverside  say their rewritable paper is based on the colour switching property of commercial chemicals called redox dyes.

The dye forms the imaging layer of the paper. 

Printing is achieved by using ultraviolet light to photobleach the dye, except the portions that constitute the text on the paper. 

The new rewritable paper can be erased and written on more than 20 times with no significant loss in contrast or resolution.

'This rewritable paper does not require additional inks for printing, making it both economically and environmentally viable,' said Yadong Yin, a professor of chemistry, whose lab led the research, which is published today in Nature Communications.

'It represents an attractive alternative to regular paper in meeting the increasing global needs for sustainability and environmental conservation.'

Heating at 115 C can speed up the reaction so that the erasing process is often completed in less than 10 minutes.

'The printed letters remain legible with high resolution at ambient conditions for more than three days – long enough for practical applications such as reading newspapers,' Yin said. 

'Better still, our rewritable paper is simple to make, has low production cost, low toxicity and low energy consumption.'

California Chemists fabricate novel rewritable paper

His lab is currently working on a paper version of the rewritable paper.

'Even for this kind of paper, heating to 115 C poses no problem,' Yin said. 

'In conventional laser printers, paper is already heated to 200 C in order to get toner particles to bond to the paper surface.'

His lab also is working on increasing the cycling number (the number of times the rewritable paper can be printed and erased), with a target of 100, to reduce overall cost. 

His research team is exploring ways to extend the legibility of the printed texts or images for more than three days to expand their potential uses.

The end of the photocopier: The lab also is working on increasing the cycling number (the number of times the rewritable paper can be printed and erased), with a target of 100, to reduce overall cost.

'One way is to develop new photocatalyst nanoparticles that become highly reductive when irradiated by ultraviolet light,' Yin said. 

'We are exploring, too, the possibility of multi-color printing. 

'The design principle can be extended to various commercial redox dyes to produce rewritable paper capable of showing prints of different colors. 

All these efforts will help increase the practical applications of the technology.'