Human hair growth
The three stages of hair growth are the anagen, catagen, and telogen phases. Each strand of hair on the human body is at its own stage of development. Once the cycle is complete, it restarts and a new strand of hair begins to form. The rate or speed of hair growth is about 1.25 centimetres or 0.5 inches per month, or about 15 centimetres or 6 inches per year.
Hair theft
This created a highly profitable market in human hair, which was said in the mid-19th century to be worth twice its weight in silver. In 1851 of hair was imported from France to England with a value of £3,621 (£ today). "The Hairdressers' Journal" reported in May 1863 that a hundred tons of hair a year was being sold in Parisian markets. Not all hair was created equal; female hair from northern Italy and Spain was especially prized for its glossy blackness and curliness. It retailed at a price of 10–12 shillings per ounce (worth about £43/€50/$67 in 2013 prices), rising to £1 per ounce (about £87/€101/$136) for very long hair. A "hair harvest" was held annually in the poorer villages of Italy, where local girls sold their hair to wig-makers. One observer of a hair harvesting event reported seeing "several girls, sheared, one after the other like sheep, and as many more standing ready for the shears, with their caps in their hands, and their long hair combed out, and hanging down to their waists."