Write an article based on this "Purchase henna hair dye. Gather your other materials. Protect your clothes, skin and work area. Make a paste with the henna powder. Divide your hair into sections. Apply the henna paste to your hair. Wrap your head. Wait. Wash it out. Be careful of staining. Avoid overuse of henna."

Article:
You can purchase henna hair dye from a number of retailers — both in person and online. Most natural foods stores and even some drugstores will carry henna hair dye. Many people swear by the hennas sold at shops that carry Indian products as these are believed to be purer.  If you buy henna from a natural foods or drugstore, read the ingredients to ensure that it only contains natural ingredients. Some manufacturers combine henna with the harmful chemicals commonly found in regular hair dyes. Note that pure henna powder will dye your hair a reddish brown color. If you’re looking to go dark brown or black, it will likely have other plants (for example, indigo) in it. Just be sure to read the label to make sure that all of the ingredients in the package are natural! If you want to use henna, remember that it is a vegetable dye, so it cannot be removed from your hair or lightened with bleach or other dyes. You’ll need a stain-proof bowl to mix the henna paste in, plus a whisk to mix the henna paste with. You’ll also need hair clips to section off your hair as you apply the paste, gloves to protect your hands, and a hair dye application brush. You will also need something to cover your hair once the henna is on: shrink wrap is a popular choice, but a shower cap or plastic bag will also do. Dyeing your hair with henna can be quite messy. Wear clothes that you don’t mind getting stained. At the very least, cover your shoulders with an old towel. To prevent the henna from staining your skin, rub petroleum jelly or a thick moisturizer around your forehead, neck, and ears. Protect your workspace with some newspapers or old towels. How you make this paste will depend upon the manufacturer’s instructions, how much henna you need, and what color you’re going for.  Common ingredients for a basic henna paste are boiling hot water, lemon juice, and the henna powder. The texture you want is similar to mashed potatoes.  Some henna manufacturers require that you let the paste sit for several hours before applying. Read the instructions that came with your henna package to see if you need to let it sit. Use hair clips to divide your hair into sections. How many sections you need to divide  your hair in depends on your hair’s thickness and length. Aim for at least six: two at the nape of your neck, two near the center of your head, and two at the top. With your gloves on and starting at the base of your neck, apply the henna paste to your hair. With each section of hair, start at the ends and work up to the roots. Once you’ve applied the paste to a section, clip the section back up so that it’s out of the way of the other sections of hair.  Be sure that you add a lot of paste to each section of hair. You want your hair to be fully saturated. You might find it helpful to apply the henna with a hair dye application brush. If it’s too chunky for the brush, don’t worry! It’s also okay to apply it with your (gloved!) hands. Many people recommend using plastic wrap to cover the henna after it’s been applied. If you don’t feel comfortable doing this, you can also use a shower cap or a plastic grocery bag. The key is to ensure that your hair is covered and close to your head. Wrapping your head is very important because it will keep the henna from drying out, which would make it stop working. How long you let the henna sit on your hair will depend on the manufacturer's instructions and how intense you want your color to be. You will likely need at least a couple of hours. Some people even leave it on overnight. Make sure that you’re wearing gloves for this part, otherwise your hands will get stained. Once you’ve rinsed all of the henna out of your hair, you can shampoo and condition it as normal. You might find it more effective to wash your hair in the sink or under the faucet in the bathtub. It will be pretty messy as chunks of henna come out of your hair, which is why many people prefer not to do it as they shower. In the first few days after you’ve dyed your hair with henna, the color may rub off on pillow cases and clothes, so be careful about where you put your head until you’ve washed your hair a few times! If you use henna too often, it can dry out your hair and will build up on your ends, making them very dark and dull. Instead of doing an all-over application, just touch up your roots.