India-based Graviky Labs made the Air Ink out of carbon soot (a major byproduct of the burning of fossil fuels) and enchanced it in order to create paint people can use for art. 

For example, a 30ML Air-Ink Pen contains 30-50 minutes of air pollution coming from cars' exhaust systems. It has been caught and repurposed to serve art instead of harming people's health, damaging our lungs and causing irreparable damage to the environment. The first Air Ink products include pens, oil-based paints and even spray paints, but other art supplies could be developed soon.

Recently, Graviky Labs partnered up with Tiger Beer, Asia's number one premium lager, to test the potentially revolutionary paints and sprays on the streets of heavily polluted Hong Kong. They invited nine artists to create murals using only the soot-based Air Ink.