Chinese scientists have invented a revolutionary new printer that uses water instead of ink on a re-writable paper.
A team of chemists from Jilin University developed the water-jet printer that takes a blank page and covers it with print.
Although the text fades within 22 hours of being printed, researchers said 40 per cent of printed pages are thrown away anyway after being read only once, 'China Daily' reported.
The printer can also switch between water and ink in case the user wants a more permanent print.
The paper used in the printer is treated with an invisible dye that becomes visible when exposed to water.
The dye slowly fades over time, with higher temperatures causing it to fade more quickly.
"The paper we used in our experiments is a common type that people can get anywhere," Zhang Xiao'an, professor and leader of the team, said.
Water-jet printing allows one page to be reprinted dozens of times, so it can help offices save money on paper.
Although chemical treating is involved, the cost is still relatively low, the report said.
"According to our calculation, dye-treating the paper that is generally used for printing adds only 5 per cent to the price. So it's very cheap," said Zhang.
