Eco-advertising uses a power washer, a stencil and the dirty London streets

From core77 via neatorama

Green Street Media is a British ad agency that emphasizes eco-friendly advertising. One medium that it uses consists of applying stenciled designs and a power washer to dirty London sidewalks. The company estimates that an ad should remain legible for 3-5 months.

When a client wants a sidewalk advertisement, rather than using chalk or spraypaint GSM uses laser-cut stencils and a high-pressure hose to blast a clean spot out of the stencil's negative space. The only materials used are the stencil and plain water.