Street Art poster by Gran OM& Co, Mexican visual arts workshop. Project ‘Propaganda & Conscience’. Poster: ‘Voix & Murs’. ‘If they cannot hear our voice, they will have to get used to reading us on their walls’. Poster measuring 60 x 90 cm - Offset print, with authenticity stamp. Open edition. Gran OM & Co, 2013. In 2006, artist OM created a visual art workshop focused on denouncing and supporting the social struggles through graphic design. In order to have an impact on the Mexican and Latin American societies, Gran OM has become a collective initiative currently including Kloer, Chauiztle, Boer, Richard and OM.