IN CONCRETE: URBAN GRAPHICS 2004-2010 - Andrew Wasserman, Alicia Candiani, Nelson Rivera, Katherine T. McCaffrey, Roberto Otero and Rafael TrellesReverse Graffiti by Rafael Trelles In 2004, Trelles developed a street art technique using a pressure hose on walls, sidewalks, and other surfaces a genre he calls urban graphic art. Today, this technique is known as reverse graffiti. From 2004 through 2010, Trelles worked nationally and internationally, creating public art with the reverse graffiti technique. Drawing on diverse voices from Rafael Trelles projects and an art history essay by Andrew