Graffiti's Long Climb From the Street to the Collection

What was once written off as vandalism now hangs, quite literally, in the category of art collectors take seriously. The shift has produced two very different paths for the artists behind it: some, Banksy chief among them, have built entire careers while keeping their identities private, letting the work stand alone. Others have done the opposite, stepping forward and building recognizable names that collectors now follow. Either way, the wall has become a canvas worth cataloguing.

With reporting from The Collector.