Johannesburg: A team of chemists has unveiled a new `water-jet` printer that uses water instead of ink.
The used paper fades back to white within a day, which enables it to be reused.
Sean Xiao-An Zhang, a chemistry professor at Jilin University in China, who oversaw work on the innovation, said that many statistics indicate that about 40 per cent of office prints are taken to the waste paper basket after a single reading.
The trick lies in the paper, which is treated with an invisible dye that colours when exposed to water, and later disappears.
The print fades away in about 22 hours at temperatures below 35 degree Celsius and quicker if exposed to high heat.
Zhang and his team used a previously little-studied dye compound called oxazolidine that yields a clear, blue print in less than a second after water has been applied.
The paper has been published in the journal Nature Communications.