Hair is a filamentous biomaterial (made of long protein chains, interacts with biological systems), which grows from follicles found in the dermis (middle layer) of the skin. It is mainly made up of keratin, which is a fibrous structural protein.

The entire human body, except for the palms of the hands and the soles of the feet, is covered with follicles that produce hair.

Each hair strand is made up of three layers: the cuticle, the medulla, and the cortex.

The cuticle is the outermost layer. It is made up of hard, tile-like cells that overlap each other. It is formed from dead cells that have turned into scales. Its purpose is to protect the inner layers and give strength to the hair. The shape of the cuticle determines how healthy your hair is. Healthy, shiny hair has a smooth cuticle. On damaged hair, the scales rise. You can soften the cuticle by using gentle heat (like a towel wrapped around your head after you get out of the shower) or acid-based hair products (which is why many hair products contain citric acid, etc.) while contrary, and lift the cuticle.

The next layer, in the middle, is the cortex, which makes up the bulk of the hair. Melanin, which are color pigments, are found here in the cortex. They determine the color of the hair fiber, based on how many there are and what types they are. The shape of the hair follicle determines the shape of the cortex, which therefore determines whether the hair is straight, wavy, or curly. The bark also retains water and is packed with keratin protein. The dyeing, perming/straightening or other styling process takes place on the bark. The innermost layer is called the medulla, although some people (with fine hair) have no medulla. Its purpose is still unknown.

Hair color is generally ranked by numbers from 1 to 10. Level 1 is generally black, while level 10 is generally blonde.

All natural hair colors are combined with percentages of the three primary colors: red, yellow, and blue. The two main chemicals found in permanent hair color are hydrogen peroxide and ammonia (this is why the color damages hair). The ammonia works by separating the scales from the cuticle. The peroxide helps oxidize the pigments. When hair color penetrates the cortex, it creates new pigment molecules, which are too large to leave the cortex. That is why it is difficult to remove the color once you apply it.

Bleaching your hair is a similar process. The peroxide softens and lifts the cuticle and then the bleach (lightener) disperses the color molecules that are in the cortex.

There are different levels of peroxide. 5V and 10V (V=volume) are deposit only. You would use them to deposit a darker color (like black) and they work by lifting the cuticle just a little bit. 20V lifts up to 2 levels and deposits color. This is the most common peroxide used. 30V elevators up to 3 levels and 40V elevators up to 4 levels. You won’t see 40V used often. It is usually only used with high lift and bleach blondes, but it is very damaging to the hair and can burn the scalp if used incorrectly.

Now, back to the primary colors…
The three primary colors, as I said before, are red, blue, and yellow. The three secondary colors are orange (red+yellow), green (blue+yellow), and violet (blue+red). Look at the way the color wheel is set up as it’s made this way on purpose. The color directly opposite a color is its complementary color. Complementary colors can intensify or neutralize each other. For example, when you bleach your hair, it often ends up a pale yellow shade. To take the yellow out, you tone your hair with a violet-based tonic to turn it a platinum blonde. This is why many “blonde” shampoos are purple. If your hair is orange, you should tone it with a blue-based (ash) toner.

Toners are basically pigments to tone your hair after bleaching. I highly recommend toning the hair after bleaching it, because it looks more finished. There are so many different varieties of toners. You can tone ash blonde, platinum blonde, neutral, strawberry blonde, etc.

Let’s say your hair is bleached but you decide you want to dye it back to brown. First you have to re-pigment the hair. If you don’t, the color will actually turn ashy/grayish and look washed out. To re-pigment (fill in) your hair, you should use reddish/gold colors that are one level lighter than your desired color. I used Paul Mitchell color and there are different formulas you can use depending on your target level. For PM, I would mix equal parts of the formula with 10V developer and apply to damp hair. Process for 10 minutes then apply target color over repigment formula (unless target formula is cool/neutral, it would wash off repigment formula). Process everything for an additional 35 minutes.

I’ll get into the different types of colors next: Permanent colors can lighten your hair by up to 3 levels, generally, and should last quite a while. High-lifts will lift the hair around 4 levels. Demi-permanent colors last around 4-6 weeks and will eventually wash out, leaving no roots. Temporary colors generally coat the hair shaft, without penetrating the cortex, so they don’t need developer. If done right, these should last even a few weeks. Little old ladies use a color rinse a lot, which is a temporary color that will just wash out the next time they wash their hair.

One very important thing to know about color that most people don’t know is that

COLOR WILL NEVER LIFT COLOR

Basically, this means that if your hair is dark brown and you want to lighten it to a light brown, you have to bleach it before it turns the color you want. I hear clients talk about this at work ALL THE TIME. They are confused because they tried to dye their own hair lighter and it turned darker. Now consider all that I have taught you so far. If your hair already has dark color molecules in the cortex, and you put another color on top of it, all you are doing is depositing more color molecules in your cortex, making it darker. The color will lift virgin hair, but not hair that is already colored.

Now I will tell you how perms and relaxers work. Always rinse before doing a perm, as that will help remove buildup and medication from the hair. While the hair is wet, you wind it on curlers (the same width as the resulting curl). Then apply the perm solution to each perm bar and allow it to process. The permanent solution is usually made from ammonium thioglycolate. The solution breaks down the disulfide bonds in your hair (which are the proteins that give your hair its shape). After you’ve processed, you rinse out the perm solution and then apply the neutralizer. The neutralizer rebuilds the disulfide bonds into the new form of the permanent rod. Ready! Now you have curly hair! Straighteners generally do the same thing, except they make your hair straight instead of curly.

Well, I hope you have learned something new and interesting about hair! There are so many other great things to learn and I’ll write about them later!

Have you been to beauty school? I always love to hear new things so if you would like to add anything to this article please comment.