An Indian startup has found a good use for air pollution: Ink for artists. The brainchild of an Indian collective known as Graviky Labs, Air Ink is a line of pens whose ink is made of recycled air pollution. Each pen contains the equivalent of between 30 and 50 minutes of air pollution generated by car exhaust. Artists have already begun using the pens to create some eye-popping works, according to Gizmodo. The innovators got the idea several years ago during conversations with the Fluid Interfaces Group at MIT’s Media Lab and presented their vision at the 2013 INK conference. The collective spent the last several years conducting their own research into the chemical processes required for extracting carbon from car emissions and recycling it into usable ink. Once they receive certification, Air Ink should begin scaling up production of the pens for commercial use.