Berlin-based art collective Raubdruckerin has been using manhole covers, vents and utility grates as ‘stamps’ for tees and bags; applying water-based, eco-friendly ink with a roller onto the cast iron covers.

On their website, the group explain, “these neglected city art[works] surprise us in their diversity, creativity of design and the careful integration into their surroundings”.

While they started in Berlin, they have expanded to other cities including Amsterdam, Paris and Lisbon. To see the finished designs and learn more, visit their official website.

[via Colossal]