Paper-Saver(TM) ink is a disappearing ink for inkjet printers. The ink erases itself after three weeks so that paper can be reused, providing pollution-free paper. It is sold as 3rd party replacement ink cartridges.

Today paper is not what it used to be. It’s not the best tool for writing, storing information, or transmitting information. Those functions have gone digital. So why do we still consume office paper at a higher per-capita rate than before the advent of computers? Why is the average document printed 5 times? Why hasn’t Business Week’s 1975 prediction of the paperless office come true? The answer is that paper hasn’t been replaced by screens; paper has become a screen. For some it’s a screen that can display 10 pages at once without scaling down the image size. For others it’s a screen without distractions in the margins. We recognized that paper is a display technology and need not be single-use only.

The problem with using paper only once is that it wastes natural resources and pollutes the environment. Using 16 sheets of paper has the same global warming effect as driving one mile. With today’s printers, people have to either work on a screen or accept the environmental consequences of printing. Blue Planet Ink lets them still print, but at a much lower environmental cost. Every time a sheet of paper is reused, the environmental impact from the paper is zero.

How it works:
The self-erasing inkjet ink is water based. The ink itself is essentially an acid-base indicator, also commonly called a pH indicator. The indicator used currently is thymolphthalein, which is blue when the pH is high and colorless when the pH is neutral or low. The ink contains a base to raise the pH so the ink is initially blue when printed.

After printing, the ink begins to self-erase as it absorbs carbon dioxide from the air. The carbon dioxide gradually lowers the pH. As the pH is lowered, the ink loses its color until it is no longer visible. All the sheets in a stack of paper self-erase. The top sheet in a stack of paper erases fastest because it has the most air flow.

The ink was awarded U.S. patent number 8,328,317 Self-erasing printing system, and development was supported by the U.S. National Science Foundation SBIR grant number 1519546.

For self-erasing ink to save paper it must be commercially viable. Fortunately OEM ink cartridges are priced notoriously high to subsidize the artificially low cost of printers. Paper-Saver ink will sell at the same price as OEM ink but with a greater profit margin because we’re not paying for the printers. Recurring revenue from the same customers will accrue because self-erasing ink is a consumable and only we can provide it. Even though conventional printer ink is notoriously expensive, in our nationwide surveys totaling 738 respondents, 77% said they would buy self-erasing ink priced at that level. Moreover, 31% would buy it even if it cost $5 more than conventional ink.