Ancient Egyptians dyed their fingernails with henna and other natural plant stains, but the first real paint for the nails was developed in China around 3000 B.C. Made of beeswax, egg white, and vegetable dyes, and sometimes gelatin and gum arabic, the lacquer was colour-coded by social rank. At around 600 B.C., gold and silver were sported only by royalty; later, red and black became the top-ranking colours. Among the Egyptians, bright red was allowed only on the highest classes. Queen Nefertiti in the 14th century B.C. painted her fingernails and toenails ruby red; Cleopatra (first century B.C.) preferred a darker red. Lower ranking men and women also wore nail varnish, but only in pale shades.
A gold manicuring set was uncovered in the royal tombs of Ur in southern Babylonia, indicating that the nobility of 2000 B.C. used well-groomed nails as a way of setting themselves off from the common labourer. Babylonian, Egyptian, and Roman military officers often took great pains with makeup before battle—curling their hair and having their nails and lips painted in matching colours.
In the early 20th century, an innovation in nail polish revolutionised it as a beauty product. Nitrocellulose was invented in the 1830s by European chemists as an explosive. Cellulose (plant fibre) mixed with nitric acid made for a highly combustible product, which chemists were able to turn into guncotton, or smokeless gunpowder. Later, nitrocellulose was used to make celluloid, the basis for film and various hard plastics. After World War I, nitrocellulose lacquers began appearing in a multitude of colours, thanks to the boom in car manufacturing. By the early 1930s, nail polishes were also available in a variety of shades, giving nails the glossy enamel finish you see today.