For the past few weeks artist Antonin Fourneau has been working at the Digitalarti Artlab in Paris creating what’s being called his Water Light Graffiti system. The device utilizes a giant matrix of LEDs embedded in a moisture-sensitive panel that when exposed to water causes the lights inside to instantly illuminate. The fun thing is that almost anything becomes a temporary paintbrush: a wet hand, a squirt gun, a paintbrush or even an atomizer. Water Light Graffiti was recently put on display in Poitiers, France and you can watch the video above to see it in use, and here’s a short clip (in French) of Fourneau showing how the entire thing was constructed. Many more photos here.