A new coating that can protect heritage sites from graffiti has been developed by The Construction and Territorial Development Unit of TECNALIA in Europe. Cultural heritage materials, buildings and statues are often porous and so susceptible to environmental erosion, but increasingly, damage by graffiti artists is a problem of esthetics and conservation. A new material - a pH-sensitive silicon-based polymer complex has been developed in the project and tested in five countries on culturally important buildings. The material is hydrophobic and so prevents water penetration, it adheres well even to porous surfaces, it does not change the appearance of the surface it coats and is resistant to sunlight, condensation, ageing and natural weathering. Importantly, the environmentally friendly composition prevents paint from soaking into stonework and other porous materials and so acts as an easy-to-clean anti-graffiti skin.