New type of paper is reprintable

Re-writable paper is not new. Scientists have been working on this for quite a while now, but up to now this has only been successful with black ink or with text which can only be read under UV light. Apart from that the inks usually fade after a few days. Chinese researchers now claim in Nature Communications to have taken a significant step forward.

They made reusable paper which can be printed in colour and can be erased and reused within six months. Their paper consists of 4 micro-layers of polymers and chemical compounds which change colour when exposed to metal salts. Depending on the type of metal salt in the ink a different colour appears. The researchers were able to make: brown, khaki, dark blue, light yellow, yellow, orange and light green.

The re-writable paper can be written on and erased for up to five times without loss of colour intensity. But the paper is not immediately suitable and available for our printers. The paper needs to be treated with a fluoride ionic solution to remove the text and this process makes commercial use more difficult. In the published paper the Chinese scientists write that they are working on a more practical solution. For example, future printers could have a removing solution in a cartridge as well as an ink cartridge.

The scientist reckon that that paper will be five times cheaper than current inkjet printing. They are also working on greener alternatives for some of the (lightly toxic) chemicals they now use. The re-writable paper would be as recyclable as ‘normal’ paper.