Safety razor become locked into buying their proprietary cartridges, for as long as the manufacturer continues to make them. Subsequent to introducing the higher-priced Mach3 in 1998, Gillette's blade sales realized a 50% increase, and profits increased in an otherwise mature market. The marketing of increasing numbers of blades in a cartridge has been parodied since the 1970s. The debut episode of "Saturday Night Live" in 1975 included a parody advertisement for the Triple Trac Razor, shortly after the first two-blade cartridge for men's razors was advertised. "Mad" magazine announced the "Trac 76", arranged as a chain of cartridges with a handle
American Safety Razor Company building at 333 Jay Street then became the new campus for the Polytechnic Institute of Brooklyn. Seeking diversification Philip Morris acquires American Safety Razor in 1960. In 1963 American Safety Razor is the first maker of stainless steel blades, which were sold under the Personna brand name. In 1968, Philip Morris, purchased the Burma-Vita Company, makers of Burma-Shave. In 1970, the first blade made with tungsten steel was introduced, the Personna 74. In 1974 American Line Brand of industrial products was introduced, expanding the company into industrial blades. In 1977, executives purchased Personna American Safety Razor Company from Philip Morris