Coffee as Ink

Curators’ Corner

Coffee as Ink

Pixels, color calibration, and ink droplet sizes — Duggal lives and breathes the specs of print production.

Well, that and coffee.

That’s why we were intrigued and excited when we heard about a printing machine that literally runs on coffee, just like us. The only ink needed to operate Rochester Institute of Technology professor Ted Kinsman’s Coffee Drip Printer is a pot of java.

“Since I always have leftover coffee, I thought it would be a fun medium to play with,” says Kinsman, whose invention can churn out low-res prints from a range of liquids, from coffee to red wine. “Just about everyone can relate to coffee, and this medium is often used to get people interested in what the machine can do.”


Which turns out to be quite a lot. While stepping motors position the drip valve over the print surface, “ink” is dispensed based on how long the valve remains open: Pixels range from 0 (no coffee) to 256 (seriously juiced up), and the largest drop (which produces the darkest pixel) requires the valve to be open for 63 milliseconds. Kinsman’s contraption can produce a total of 53 shades.

“The machine allows experimentation with drip height, drip size, drip chemistry, spacing of drips, and especially the paper that the drips fall on,” Kinsman told PetaPixel.


For “very good” prints, he recommends changing the chemistry of the ink so that the liquid has a low wetting angle on the paper. The Arduino-microcontroller-powered machine can print images up to 80 x 100 pixels large, although each print usually requires a full day to dry completely.

Check out the printer in action below. Would your ink of choice be coffee or something else? Let us know in the comments!


Trending news story – community support post – service not available at Duggal.