All about Henna
Henna (Lawsonia inermis) is a flowering plant used since antiquity to dye skin, hair, fingernails, leather and wool. The name is also used for dye preparations derived from the plant, and for the art of temporary tattooing based on those dyes. Additionally, the name is misused for other skin and hair dyes, such as black henna or neutral henna, which do not derive from the plant.
Preparation and Application
Whole, unbroken henna leaves will not stain the skin. Henna will not stain skin until the lawsone molecules are made available (released) from the henna leaf.
Fresh henna leaves will stain the skin if they are smashed with a mildly acidic liquid.
The lawsone will gradually migrate from the henna paste into the outer layer of the skin and bind to the proteins in it, creating a fast stain.
Since it is difficult to form intricate patterns from coarse crushed leaves, henna is commonly traded as a powder made by drying, milling and sifting the leaves.
The dry powder is mixed with lemon juice, strong tea, or other mildly acidic liquids to make a preparation with toothpaste-like consistency, which can be used to make finely detailed body art.
The henna mix must rest for 6 to 12 hours before use, to release the lawsone from the leaf matter.
Essential oils with high levels of monoterpene alcohols such as tea tree, eucalyptus, cajeput, or lavender will improve skin stain characteristics.
The paste can be applied with many traditional and innovative tools, including resist, shading, thick-paste, and cellowrap techniques.
A satisfactory stain may be achieved within minutes, but the longer the paste is left on the skin, the stronger the stain will be, and it may be left for several hours.
To prevent it from drying or falling off the skin, the paste is often sealed down by dabbing a sugar/lemon mix over the dried paste, or simply adding some form of sugar to the paste.
This also adds to the colour of the end result, increasing the intensity of the shade.
At the end of the procedure, the dry paste is simply brushed or scraped away.
Henna stains are orange soon after application, but darken over the following three days to a reddish brown.
Soles and palms have the thickest layer of skin and so take up the most lawsone, and take it to the greatest depth, so that hands and feet will have the darkest and most long-lasting stains.
Steaming or warming the henna pattern will darken the stain, either during the time the paste is still on the skin, or after the paste has been removed.
Chlorinated water and soaps may spoil the darkening process: alkaline products may hasten the darkening process.
After the stain reaches its peak color it will appear to fade, as the stained dead cells exfoliate.