Visitors to Warhol’s Factory in New York City were often invited to sit for a screen test. Starting in 1964, he made more than 500, of which, so far, 277 have been preserved. The Factory camera (not necessarily operated by Warhol) would record the subject on a single unedited one-hundred-foot 16 mm silent cartridge. The tests were shot at sound speed (twenty-four frames per second), but Warhol wanted them projected at silent speed (sixteen flames per second), so they take longer to see than they did to make. The sitter was often instructed not to move. Most disobeyed.