Office waste is a part of doing business. Although our world has become increasingly digital, paper copies of documents are still often used for reasons that nobody entirely understands. It's incredibly wasteful: about 40 percent of these documents end up being tossed into the trashcan shortly after being read. Also, the ink to print those documents isn’t cheap. A group of chemists from Jilin University in China, though, have a solution: they invented a printer that uses water instead of ink and paper that becomes blank again after 22 hours, making it 100 percent re-usable.
The most important element of this invention is the paper: it comes pre-treated with an invisible dye called oxazolidine that reacts to the water from the printer, creating a clear print that lasts for about a day. After that, the print slowly fades and becomes clear again, making it capable of being used as many times as needed. The only necessary component to make that happen is a temperature below 95 degrees Fahrenheit. The printer works like a standard inkjet, but instead of having to purchase a costly cartridge when it gets low, you just fill up its cartridges with water using a syringe.
The chemists figured that if one piece of paper is used about a dozen times, the cost would be about 1/17th of printing methods with an inkjet printer, even considering that the pre-treated paper would cost more than standard paper. Not only that, but there is nothing toxic present in the process, and re-using the paper is good for the environment. At present, the only colors the chemists have worked with are blue, magenta, gold and purple, but they’re working on adding full-color and improving resolution. They are also working on a device that can heat the paper up to higher temperatures to make it fade even faster.