Commercially produced anatomical studies of bodybuilders and nude models became a standard cosmopolitan product in the late 19th century. Poor art students initially used them in place of live models. Eugen Sandow popularized this type of photography that emphasized the Greek ideal of meticulously proportioned muscles. There was a thin line between bodybuilder and homoerotic photography and this artistic movement was often geared toward the closeted gay male audience. Censorship pushed the images underground and the sport of bodybuilding divorced itself from its link to these types of images by becoming a legitimate sport in 1939.