Before you get into coloring hair, it’s useful to understand the structure & chemistry of hair.
Basics of Hair:
The hair shaft is composed of three major parts: the cortex, medulla, & cuticle.
Cortex: Contains melanin and moisture.
Melanin is what determines hair color.
There are two main pigments:
- Eumelanin- black & brown pigments
- Pheomelanin- red & yellow pigments that give your hair warm tones
Medulla: Innermost layer of hair shaft.
Cuticle: Protective, outer layer of hair shaft. Made up of little scales that lay flat or are raised.
Smooth vs Raised Cuticle:
- Smooth/closed cuticles result in healthy hair since moisture and
shine is locked in.
- Raised cuticles results from the use of chemical products.
Hot temperatures will also raise the hair cuticle.
pH of hair:
Healthy hair will have a pH between 4 and 5.5.
Acidic products will promote closed cuticles while
Alkaline products will promote open cuticles.
Hair porosity is the ability of your hair to absorb moisture.
You can perform a simple test to determine the porosity of your hair. All you have to do is drop a clean hair strand into a glass of water and see where the strand is after a couple of minutes.
|
Porosity |
Porosity Test |
Moisture |
Hair Characteristics |
Hair Products |
|
Low |
Floats on top of water. |
Resistant to absorbing moisture. |
Hair is resistant to chemical services. Hair does not absorb products. |
Products that are more alkaline are recommended for this hair type. They will open up the cuticles so that moisture can be absorbed. |
|
Medium |
Stays in the middle of glass. |
Moisture can easily be absorbed and retained in hair. |
Hair is healthy and shiny. |
Occasional use of hair treatments is recommended. |
|
High |
Sinks immediately. |
Easily absorbs moisture but simultaneously releases it. |
Hair tangles easily due to raised cuticles. Hair feels dry and is easily damaged. |
Since high porosity hair can lose moisture easily, leave-in conditioners and sealers are highly recommended. |
