Peregrine Church, street artist created a series of public works of street art called Rainworks. Like a new modern version of invisible ink, super hydrophobic coatings can also be used to create hidden street art that stays invisible until it gets wet.
Church has creates unique artwork spontaneously because he has been assured by the city authorities that his art works are legal. The coating is non-toxic, non-permanent, only sometimes visible, and his works dose not advertise anything. Here are some pictures of art done by Peregrine Church