Rescuing street art from vandals' graffiti. Around the world, street art by famous and not-so-famous artists adorns highways, roads and alleys. In addition to creating social statements, works of beauty and tourist attractions, street art sometimes attracts vandals who add their unwanted graffiti, which is hard to remove without destroying the underlying painting. Now, researchers report novel, environmentally friendly techniques that quickly and safely remove over-paintings on street art. Source 4k.