The book aims to analyse, investigate and recognise two of the contemporary artistic avant-garde through a multi-disciplinary perspective. Writing first and then the Street Art were always fed from every corner of reality, indiscriminately and free of any cultural debt . Today more than ever, this investment can be seen in architecture, urbanism, semiotics, sociology, anthropology and art scene. The difficulty of structuring a unanimous critical profile lies mainly in the multiplicity and dynamism which the two movements have drawn, and anticipated styles, environments, attitudes and collective sensitivity. With over 40 years of history and street experience, Writing and Street Art have had the merit to reproduce and criticise the entire global system of visual communication. The FRONTIER -The Line of Style project is ideally and historically connected to the show Arte di Frontiera New York Graffiti (Bologna, 1984). The most important figures of New York Graffiti- Art took part at this show and later they became very famous artist as Jean-Michel Basquiat, Keith Haring, Kenny Scharf and Futura 2000. FRONTIER has been structured as an open and evolving platform based on two complementary phases: the first phase is focused on the demonstration of the artistic value of Street Art and Writing, displayed by the creation of 13 monumental walls (Andreco, Cuoghi Corsello, Daim, Dado, Does, Eron, Etnik, Hitnes, Honet, Joys, M-city, Phase2, Rusty); the second one is an international symposium for a theoretical and critical examination of the two disciplines.