Our digitalized world gives us the opportunity to save money and resources by organizing tasks on a computer. But according to a study carried out by theGerman Ministry of Environment Germans use about 250 kg paper per year and capita. Especially in offices the paper waste is enormous: More than 10.000 sheets are printed each year. Mostly they end up in the bin after being read once. A Chinese team of scientists has now developed a smart and resource-efficient alternative: Rewritable paper that can be printed on with water instead of ink.

Sean Zhan, professor at the Jilin University in China invented the new printing technology. “The greatest problems of our time are the energy crisis, global warming, and of course the destruction of our environment. Excessive paper consumption is directly connected to that”, says Zhang. In order to counteract the waste of paper the scientist and his team found a practical solution.

Water ink can be used on any inkjet

The result of their research is intelligent printing paper that is coated with invisible ink. When the paper comes in contact with water the ink becomes visible and lasts for about 20 hours. After that it disappears and the paper can be used again. Thus one sheet of the innovative paper can be re-used up to 50 times. Especially handy is that a new printer is not needed since water works with normal inkjet printers. This leads to a cost saving of 99 per cent in comparison to printing with regular ink.

The concept of reusable paper is not new: Many attempts have been made to reduce the usage of paper in the past. But until now the solutions were either very expensive or toxic substances were needed. Sean Zhan’s approach for the first time combines economic with ecologic aspects.

“From our point of view we paved the way for sustainable printing processes”, the Chinese team of scientists sums up their invention. The future will show whether the water printer takes root in our offices.