As an advertisement illustrator in the 1950s, Warhol used assistants to increase his productivity. Collaboration would remain a defining (and controversial) aspect of his working methods throughout his career; this was particularly true in the 1960s. One of the most important collaborators during this period was Gerard Malanga. Malanga assisted the artist with the production of silkscreens, films, sculpture, and other works at "The Factory", Warhol's aluminum foil-and-silver-paint-lined studio on 47th Street (later moved to Broadway). Other members of Warhol's Factory crowd included Freddie Herko, Ondine, Ronald Tavel, Mary Woronov, Billy Name, and Brigid Berlin (from whom he apparently got the idea to tape-record his phone conversations).