Alexandre Farto, aka Vhils, is considered one of the top urban artists in the world. Like many street artists, he started out painting illegal graffiti back when he was 13. But by the age of 16, the Portuguese artist was already questioning what he was doing and looking for his signature style. “I wanted to push what I was doing in the public space,” he says. “I sort of realised that all of us were adding layers on walls … they were accumulating the layers of changes. “I came up with the idea: instead of adding I would remove the layers of paint onto the walls.” Pinta Malasaña: Street artist…