Henna is a semi-permanent dye that is prepared by processing the leaves of a tropical shrub - mignonette tree or henna tree. Henna is prepared in a powdered format by drying the leaves of the henna plant. At present, henna is used widely as a natural dye to colour hair as well as create body arts.  While creating henna designs and tattoos, henna penetrates only the top layers of the skin. The dye needs about 48 hours to make the stain darken properly. Also, the strain fades gradually over the next few weeks.