The fine henna powder derived from the plant Lawsonia inermis has been used for at least 3,000 years, since ancient Egyptians used it to dye their nails and hair. Over time, the practice evolved into the body art of mehndi, a sacred practice from Africa to Southern Asia. In this practice the powder is made into a paste that forms the medium to paint intricate patterns on the hands, feet and other body parts for weddings and other celebrations.
Lawsonia inermis is a native bush found all across the Middle East and the Nile River area of Africa. The leaves of the bush are dried out and then pounded into a fine powder that varies in shades of green. When mixed with water, the resulting paste is placed in a squeezable container and squeezed through a small spout in the lid. This paste forms a hard outline that dries and can be flaked off after about 10 or 20 minutes. Left behind will be an orange-brown pattern of the artist's choosing that will be visible for as long as a week.
Henna powder and water makes the paste, but some henna artists use special tricks to make the final result darker and longer-lasting. Some apply a moisturizing lotion or cucumber peel over the henna after application to keep the dye moist for a longer period to darken the skin. Others also spray on a mixture of lemon juice and sugar water so that the skin does not have to be touched after the henna is applied.
According to several henna vendors, it does not matter how green the shade of the henna powder is. The best staining can result from a lighter shaded powder. According to experts, the best way to ensure a deep mehndi stain is to stick with a brand that has worked well in the past. Even then, however, it is possible for the coloring to change from harvest to harvest and company to company.
Another common use for henna powder through history is as a hair and nail dye. According to the Earth Henna Web site, henna powder was used in cosmetic rituals performed by the Egyptian pharoahs. Even in 2011, it is commonly used to dye the hair and hooves of horses as well as the hair and nails of humans. The ingredient also is part of some store-bought hair dye solutions. Though it darkens the skin, the dye in hair often has a lightening effect.