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Hair structure. Hair colour molecules and Ph

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Hair structure. Hair colour

Hair Structure: hair colour Molecules and Ph:

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.  Tyrosine 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 two 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.

As a follow on from the previous topic I hope that this topic answers some questions and fils in any gaps about the hair colouring process

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

We also have to know the ph of the products we are using trusting that a product with no ammonia is safe not always the way forward. For all these products are an alkaline and so open the or lift the cuticle to some degree.

Please note:

Take time  to look at the chart and see where the various applications we apply sit . A demi application developer will sit at the same level as hydrogen peroxide on this chart.

Understanding the Ph environment

Healthy hair should have a Ph of 5 to 5.5  when we introduce an alkaline be it Ammonia which comes in many different strengths the stronger the more it will open the cuticle the same can be said for other colour drivers MEA, Dealcoholised grain products, all serve the same purpose to manipulate the Ph the stronger the  product the more the cuticle will be opened and the more damage can be done.

it is essential after a process to re balance the hair and close the cuticle and restore that natural balance of 5.5.

This can be done with a chemical balancing product these normally have a Ph of 2.5 when introduced to the hair it will close the cuticle and restore the ph balance of the hair to 5.5.

Always be aware to consider the hair condition and assess during consultation before deciding on any chemical service knowing and understanding the Ph of hair is key to keeping it healthy and allowing colour retention or retaining moisture after the perming process.

Ok the Colour bus had a brief stop to review Ph now we can move onto developers with so much more knowledge of the colouring process.


This really is such a huge topic and so important choosing the correct strength is the key to success. Developers play such a huge role in the degree of lift and deposit we decide upon, allowing us to expose the pigments we utilise in the hair colour process. The formulation we chose to attain our target colour is a a blend of chosen colour level of developer timing. It’s just like baking the perfect cake! Mess with the recipe it will fail.

Lets work off an example of level 6. Dark Blonde. 6N on most  international colour charts

Depending on the level of peroxide we opt to use. We are going to introduce colour or add undertone from the hairs natural Pigment. {remember level 6 } This gets a little complicated, mainly because in some circles we are mislead as to lift we should expect, from any given strength or volume of  Hydrogen Peroxide. 10 volume or 3% Peroxide: In some circles it’s suggested that it does not lift. I would disagree with this thinking.

The lift you get, is enough to expose the pigment in the hair at that given level. So on our level 6 we would expose Red Orange, by Introducing this warmth into our equation. We have to decide on the role  it plays, how will it influence our colour.

Do we want to Utilize or neutralize the shade exposed? At this point we should consult our shade chart and yes the colour wheel, choose the shade to do the job not just the shade that you like in the swatch! The higher the volume of peroxide the more lift the more pigment to consider.


Take a look at a colour wheel if 10 is the lightest then it sits in the yellow segment.

So working from our level 6 what shade would we expose trying to get to level 10? is it possible to get their? lets see.

* 10=  pale yellow off chart

* 9 =    yellow

*8  =     yellow orange

* 7 =    orange

* 6 =    red orange

And so on down the scale.

Level 6 + 10 vol 3% 1 level  still level 6 but with pigment exposed. red orange

Level 6 + 20 vol 3% 2 levels through level 6 up to level 7 orange pigment exposed.

Level 6 +  30 Vol 9% 3 levels through level 6 and 7 into level 8 Yellow Orange pigment exposed.

Level  6 + 40 vol 12% 4 levels through level 6, 7, 8. and into level 9 exposing yellow but still a warm yellow.

4 levels of tint lift. Will not give you lift from level 6 to level 10 you will always struggle with the issue of warmth. { even with a high lift Blonde using adjusted formula with a violet base to neutralize the pigment exposed}.

You should be able to see from this example, that as we lift hair from it’s natural level we expose pigment.This exposed pigment becomes part of our colour formulation,  seeing as we have introduced this pigment into the colour equation  we have to  decide do we want to utilise it or neutralise it. thus creating our target colour.

At this juncture it’s time for the bus to stop. So we can take time to review and digest the very key points raised for creating perfect colour.


Ask your self this question which is the stronger 10 volume hydrogen peroxide or 40 volume?

be honest. I would say that 75% would say 40 Volume!

The fact is they are both the same. the only difference is the 40 vol stays active for longer.[see timing chart]

Think of it like this you have a glass of water in each hand. One glass has 1 alkali dissolving tablet in it this represents 10 vol. The second glass has 4 alkali dissolving tablets in it. This represents 40 vol strength wise they are the same, the only difference is the 4 tablets will fizz for longer.

The difference is not the strength is the longevity of the action in this case lifting! so we are back to formulation and timing.

Having made it this far on our Colour bus journey.We can now appreciate the careful balance that is hair colouring. Having a fuller understanding of the hair’s structure, how we can manipulate it’s Ph, to facilitate the hair colour process. Have a better understanding of lift deposit and how to utilise and neutralise the pigments we expose and use towards out target colour.

You can see the hair colouring process is quite complex and does require thought and knowledge when trying to achieve the very best results. It’s a balance between skill, knowledge, creativity, consultation, and formulation. in what order ? well you decide.



Mike B2MR


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