"Lotty Rosenfeld. Esta línea es mi arma" for the first time provides insights into the personal archive and family history of the Chilean concept artist, feminist, and political activist Lotty Rosenfeld (1943-2020). Influenced by her family's life in exile, growing up in the shadow of loss and resistance, she developed a radical artistic practice under the Pinochet dictatorship in the 1970s. Using the simplest of resources-adhesive tape, lines, and crosses-she transformed streetscapes into places of protest and collective memory. Her "symbolic file of disobedience" brought into question the visual logic of power and transformed art into an instrument of political involvement. The publication combines personal memories with public statements and traces the Rosenfeld family's journey from a bourgeois Jewish life in Breslau through exile to a new beginning in Chile-and shows why her white line was more than just a symbol: it was a weapon of resistance.