Men had for some time carefully groomed their hair to give it shine. But in the 1920s a smooth glossy finish called the patent leather look became very popular. Film stars such as Rudolph Valentino (1895–1926) and George Raft (1895–1980) wore the patent leather look and helped spread its appeal. Men slicked down their short hair with grease to make the flat, perfectly styled look. Some men added a stiff wave to their plastered-down hair. Most men parted their hair on the side, but some men, especially those losing their hair, used a center part. The patent leather look was worn most often with a clean-shaven face but a pencil-thin mustache could also accompany the look. The look was a perfect example of the desire for men to wear short, neatly-styled hair throughout the decade.
Corson, Richard. Fashions in Hair: The First Five Thousand Years. London, England: Peter Owen, 2001.