Hair structure. Hair colour molecules and Ph

01 Nov

Back2myroots : A place to share thoughts and grow idea’s. B2MR

Hair Structure:

To understand the dynamic’s of hair colour, the how and why’s we need to look deep into the hair’s inner structure. Look at it’s layers and how they are affected and changed during the hair-colour process.By better understanding these functions and changes,we can avoid common hair colour problems and achieve the best possible results.

The Cuticle

The protective outer layer of the hair shaft is called the Cuticle.

The cuticle is made up of translucent overlapping layers of keratin protein.

The main functions of the cuticle are






The cortex

The cortex contains keratin protein consisting of 19 amino acids,these long amino acid chains give the hair it’s elasticity. Two of key amino acids we effect in the colour process . Tyrosien this is key to hair colour pigment retention. Cysteien found in the hair’s helix helps with curl formulation effected in the perming process. Keratin is a natural fibrous protein cross-linked by sulfur bonds [cystine].

The Medulla

The medulla is the inner layer of the center of the hair shaft, it is comprised of a softer keratin than the cortex.

The cellular structure is similar to that of a raw sponge and is part of the bodies excretory system, eliminating toxin’s from the blood stream. This is why in the consultation process we have to have full disclosure with regard to medication, drugs, that could be present in the hair, and could effect the chemical process we are going to perform.

Well the colour bus moves on  towards Developers lets touch on types of pigment.

Types of Pigment

Artificial pigment is categorised into tow groups:

*Direct pigment

*Non-Direct pigment

Direct Pigment

Direct pigment or Direct dyes are, large fully oxidative colour pigments. Due to the fact that these dye pigments are fully developed they are too large to be readily absorbed through the cuticle into the cortex. They tend to lie on the outer shaft of the hair, in some cases depending on the chemistry of the colour they may have enough alkaline to partially open the cortex for partial deposit.

By design they are stains temporary colour semi permanents. [more to follow on these types of colour]

Non direct Pigment

Non-direct pigment is a molecular colour system utilising small undeveloped pigments to achieve a colour change.

The molecules pass through the Cuticle layer[with ease due to there size] entering the cortex where interaction with other oxidative ingredients [ alkaline, hydrogen peroxide,] creating colour change.

How so? The formulation is our tube of colour in this case our non direct colour pigments mixed with a chosen level of hydrogen peroxide.

Most permanent hair colors use a two-step process (usually occurring simultaneously) These step’s serve to remove the original color of the hair and then deposits a new color. It’s essentially the same process as lightening, but it’s working with the hair’s natural pigment, as it gentle lightens the pigment  to attain a target colour, colorant is then bonded within the hair shaft. Ammonia [or another alkaline substance] are the alkaline chemical that  gentle opens the cuticle and allows the hair color to penetrate the cortex of the hair. It also acts as a catalyst when the permanent hair color comes together with the peroxide. Peroxide is used as the developer or oxidizing agent. The developer lifts pre-existing color. Peroxide breaks chemical bonds in hair, releasing sulfur, this can account for the characteristic odor of hair color unless masked by other added ingredients . As the melanin is decolorized, a new permanent color is bonded to the hair cortex. Various types of alcohols and conditioners may also be present in hair color. The conditioners  and restoring the hair’s natural level of Ph, We close the cuticle after coloring to seal in and protect the new color. Timing and formulation are the key to effectiveness of any colour application.

Non-direct pigments only affect the natural colour pigments [melanin]and have little or know staining effect. they tend to be found in Demi colour and permanent colour formulations.

This creates long lasting,vibrant hair colours.

Here we are on the colour bus so many stops to make , for our part we are just the tour guides, you as passengers can get on and off as you please. You become the drive when you choose the route, the topic’s of interest to you, when you decide to do the work, decide to use this information as tool to update your skills and knowledge.

The more we put this together the more the realisation of how big a topic we have to share with you.

So next stop developers but we feel to tie developers in with hair structure and pigment we have to touch on the subject of the Ph of hair and role it plays.

The Ph of hair:

When we do any chemical service on the hair be it colour, perming, relaxing, we have to create an environment that enables us to get below the surface layer the cuticle layer of the hair ,

This is the outer layer that serves to protect the inner structure from both damage and moisture loss,

the inner layer being the cortex and Medulla.

Once we have decide on the service we are going to perform in this case colour the formulation we choose will dictate the amount of deposit the more we open the cuticle the deeper the deposit.

So understanding Ph, lift, deposit, is key to being able to perform outstanding colour services.

The Ph scale tells us the working environment of the hair and helps us determine the ideal product for any given hair type.


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