The Permanent Cosmetic Hair Dye (Vegetable Dyes, Metallic Dyes)
There are three kinds of permanent hair colourants: vegetable dyes such as henna, metallic dyes such as those used to gradually cover grey hair, and the aniline dyes or oxidation tints, which include most of the colourants used professionally in salons.
The Vegetable Dyes
Henna is the best-known, since its use dates back thousands of years. Taken from the Lawsonia plant, which is indigenous to Africa and Asia, henna varies in colour depending on which country it comes from. It can be strong orange in colour, as Moroccan henna, or a deep red, as the henna that comes from Iran — the most sought-after in the world. The plant is harvested, dried in the sun, and then crushed into a greenish powder, which is what one puts on the hair. It coats the hair shaft’s cuticle a reddish colour. (more…)
