Hair, in fact!
The thin outer layer,or cuticle, of the hair has 5 to10 overlapping keratine scales arranged in a fashion similar to fish scales. Under the cuticle layer lies the cortex.This is a dense, tubular layer of keratin that provides strength and holds the granules and melanin or pigment. Heredity determines the color and diameter of our hair, and time and health factors may alter the initial recipe. A well balanced diet and exercise are necessary to maintaining healthy locks.The powdered leaves of henna are applied as a thick paste to clean and dry or towel-dried hair. If the henna is too watery, it will drip and stain your face and neck. If it is too dry, however, it will form tiny balls that fall everywhere, reserve extra warm water to add as the paste dries.

For those with coarse, curly, or gray hair, a second application or double process of henna may be necessary. Use plain henna paste first; rinse the hair after five minutes. Then reapply the henna (plus any add-ins you desire), wait at least an hour, and rinse again.

Here's a handy gauge of the quantity of henna you will need.

Henna powder (army green color): 2-3 ounces (60-90 g) for short, fine hair; 3-5 ounces (90-150 g) for medium length hair; 5-8 ounces (150-240 g) for long hair.

Boiled spring -or distilled water, cooled to a warm temperature.

In a bowl, mix the henna powder with enough warm water to form the consistency of chocolate pudding.

To avoid tinting the skin around your hairline, clip back the hair and apply cream or oil around the perimeter of your face; include the tops of your ears and back of your neck. You can also place a thin roll of cotton over this cream to soak up any extra henna paste. If you drip henna on your skin, try washing with a bit of shampoo or lemon juice as soon as possible.
Put an old T-shirt and disposable rubber or plastic gloves. Place paper towels on the counter. Section your hair into 1-inch (25mm) parts. Using a brush or your fingers, apply henna paste to the roots of your hair. After all are covered, work the henna paste down and hair shaft.

Cover your hair with a shower cap and top of it with an old scarf and top with an old towel or scarf. Allow the henna to saturate your hair from anywhere from 2 to 24 hours (depending on the intensity of the color you want. Because henna is activated by heat, you can shorten the process by using an electric hair dryer for at least 30 minutes at a comfortable setting. Or, try sitting in the sun for 30m minutes!

After the allotted time, rinse the henna paste from your hair until the water runs clear. If possible, do not immediately use shampoo. Let the hair dry naturally.

Later in the same day, shampoo with an acidic pH shampoo. Towel-dry, then massage a small amount of coconut oil into your hair. Cover your hair with an old shower cap and leave the oil for at least one hour, then rinse.

Caution
To apply henna on hair, you will need only the henna powder and several simple-to-gather items that you probably already have around the house. Avoid using metal bowls or utensils for mixing, as they can react with the natural chemicals present in the henna.

Want color variation?
In order to vary your hair color you can stir some of these popular color inhancers in to henna paste mixture: Allspice, cinnamon, or nutmeg, Apple cider vinegar or lemon juice, Egg yolk or whole egg, Cloves, Cognac, Tea, Coffee and Olive Oil. For detail please
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