A Complete Information to The Science of Hair

Let’s speak about primary hair concept– the science of hair and the way it all works!

In magnificence faculty, hairstylists be taught all the pieces you’ll be able to think about about hair. This consists of hair colour concept, chemistry, anatomy, hair construction… and even the enterprise aspect of working a salon.

Truthfully, all of this stuff are tremendous vital. Are you able to think about what occurs to your consumer’s scalp should you don’t combine the bleach accurately? Dangerous, dangerous issues can occur with out the correct coaching…

However, haven’t any worry! This text will infuse you with all the essential hair data you want!

So do you suppose you will have what it takes to do hair? Maintain studying to seek out out…

💡TIP: Pin this text to your Hair Coloration board on Pinterest so you’ll be able to at all times come again when that you must! 👇🏼👇🏼👇🏼

There's so much more to hairstyling than you realize. Find out everything you need to know about basic hair theory with this ultimate guide.

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Hair Idea 101

Human hair under the microscope.

So what’s hair?

Hair is a filamentous biomaterial, primarily composed of Keratin. It grows from hair follicles discovered within the dermis and covers many of the human physique.

It’s additionally a singular attribute of mammals.

Hair Construction 101

Every strand of hair consists of three separate layers: the cuticle, medulla, and cortex.

Hair Structure: Cuticle, Medulla, Cortex

The Cuticle

The cuticle is the outermost layer, containing arduous, shingle-like cells that overlap one another. Its function is to strengthen the hair and shield the internal layers.

This layer determines how wholesome your hair seems to be.

In wholesome hair, the scales lay flat on one another, giving the hair a modern, shiny look. Quite the opposite, broken hair has raised scales, making the hair seem like tough and textured.

That being stated, you’ll be able to alter the state of the cuticle in numerous methods. Let me clarify…

Gentle warmth (like a towel wrapped round your head after the bathe) or acidic hair merchandise clean down the cuticle; alkaline merchandise swell the hair and lift the scales again up.

The Cuticle of Healthy Hair vs Damaged Hair

The Cortex & Medulla

Beneath the cuticle lies the cortex. This layer resides in the midst of the hair shaft and makes up the majority of the hair.

Melanin, aka colour pigment, is discovered within the cortex and determines the colour of the hair. Moreover, the form of the cortex determines if the hair is straight, wavy, or curly.

This layer additionally holds water and keratin proteins. All chemical therapies (hair colour, perms, relaxers, and so on.) happen within the cortex.

Final however not least, the innermost layer of the hair is named the medulla, and its function remains to be unknown. In actual fact, you received’t even discover it in individuals with tremendous hair.

Now that you’ve got a strong understanding of hair construction, let’s dive into hair colour concept…

Hair Coloration Idea 101

Hair colour ranges are organized from 1-10. Degree 1 refers to black hair, whereas degree 10 is the lightest shade of blonde.

Hair color numbers/level chart system.

Coloration Idea

All naturally occurring hair colours are constituted of completely different mixtures of the three main colours: crimson, blue, and yellow.

Color wheel or color circle with twelve colors

Okay, so check out the colour wheel. Do you discover that the first colours divide it into three sections? This makes it a lot simpler to visualise colour concept.

Now we are able to see the secondary colours, that are made by mixing two main colours collectively; they sit instantly between the 2 main colours on the wheel.

These colours are inexperienced (blue + yellow), orange (crimson + yellow), and violet (blue + crimson).

The cool factor concerning the colour wheel is that it exhibits you ways colours work collectively; the colour that sits instantly throughout from one other is its complementary colour.

That is tremendous vital with hair colour… as a result of complementary colours both intensify or neutralize one another.

So take into consideration this… when hair is bleached, it often turns pale yellow. A violet-based toner will cancel out the yellow tones and make the hair seem platinum-blonde.

Likewise, orange hair could be toned with a blue (ash)-based toner. That is why “blonde” shampoos are inclined to have blue or purple pigments in them.

How Hair Coloration Works

Two important chemical substances present in everlasting hair colour are hydrogen peroxide and ammonia.

Ammonia separates the cuticle scales, permitting the colour to get contained in the hair; peroxide oxidizes the pigment. When hair colour penetrates the cortex, it deposits colour molecules too large to flee.

That is why it’s arduous to get colour out as soon as you place it in.

Bleaching hair entails an analogous course of. The peroxide softens and lifts the cuticle so the bleach can go in and disperse the colour molecules within the cortex.

Developer is the peroxide part we combine with hair colour once we’re prepared to use it… and there are completely different ranges of developer that every do various things.

5V and 10V (V=quantity) are deposit solely, that means they will’t raise the hair to a lighter shade. Subsequently, you must solely use these guys when going darker.

20V lifts as much as 2 ranges and deposits some colour. That is essentially the most generally used developer and is greatest for gray protection.

Likewise, 30V lifts as much as 3 ranges and 40V as much as 4 ranges.

40V isn’t used typically, because it causes essentially the most harm and may injure the scalp if misused; it’s sometimes solely used with high-lift blondes and bleach.

Kinds of Hair Coloration

There's so much more to hairstyling than you realize. Find out everything you need to know about basic hair theory with this ultimate guide.

When enthusiastic about what kind of colour to make use of, take into account how lengthy it’ll final, how a lot harm it causes, and if it might probably lighten your hair or not.

Some hair colours are “deposit” solely, whereas others can “raise” your hair to a lighter shade.

  • Everlasting colours can raise hair as much as three ranges and final till the hair grows out.
  • Excessive-lift colours can raise the hair about 4 ranges; these are kinds of everlasting hair colour meant for lighter blondes.
  • Demi-permanent colours final about 4-6 weeks and ultimately wash out and not using a line of demarcation; these can not raise hair to a lighter shade.
  • Semi-permanent colours solely coat the hair shaft with out penetrating into the cortex. When utilized accurately, these colours can final a couple of weeks.
  • Short-term colour washes out within the bathe.

There's so much more to hairstyling than you realize. Find out everything you need to know about basic hair theory with this ultimate guide.

Coloration Correction 101

So… typically your colour doesn’t prove the way you anticipated. What do you do then?

Whereas a number of components are at play (if the hair is mild sufficient, how even the applying was, situation of the hair, and so on.), hair toners can often assist. These distinctive hair colours are designed to deposit pigment and alter the tone.

As beforehand talked about, you should utilize an ash colour to neutralize the brassy tones… or a violet-based toner to kill the yellow hues.

💡RELATED: How To Use a Hair Toner For Brassiness

Except you want yellow hair, you must at all times tone bleached hair. That is the way you get the completely different blonde shades like ash, platinum, strawberry, and so on.


Let’s say you will have platinum blonde hair however wish to go darker. You’re gonna wanna repigment or “fill” the hair first… in any other case, you’ll find yourself with light, ashy hair colour.

To repigment the hair, you usually wish to use reddish-gold colours which can be one degree lighter than the specified colour.

Whereas all colour traces are completely different, you’ll be able to often discover a “repigmentation” components for the particular colour you wish to use. All the time comply with the instructions for the most effective outcomes.

An instance repigmentation course of: For Paul Mitchell colour, you’ll combine equal elements of the formulation with 10V developer and apply to damp hair.

Course of for 10 minutes after which apply the goal colour over the repigmentation components (until the goal components is cool/impartial, then wipe off the repigmentation components first).

Course of the entire thing for an extra 35 minutes, after which BAM… repigmented hair.

There’s a motive why hair colour specialists receives a commission the large bucks…

The Golden Rule of Hair Coloration

An excellent vital factor to find out about hair colour concept is that colour is not going to raise beforehand coloured hair predictably.

This principally implies that in case your hair was beforehand coloured darkish brown, and also you wish to raise it to a lighter colour, you’ll need to bleach/strip your hair earlier than you’ll be able to colour it.

Contemplate all the pieces we’ve talked about to this point… In case your hair already has darkish colour molecules within the cortex, and you place one other colour on prime of it… you’re simply smashing extra colour molecules into the cortex.

Coloration will raise virgin hair, however not hair that has already been coloured.

Perms / Straighteners 101

Woman getting permanent wave done on her hair.

We are able to’t speak about hair concept with out relating perms.

First off, there are two kinds of perms: acid and alkaline. Alkaline perms are used for normal-to-coarse hair, whereas acid perms are higher for broken, coloured, and/or finer hair sorts.

Acid Perms are much less damaging however require outdoors warmth to course of.

Find out how to do a Perm

Earlier than beginning a perm, the hair ought to at all times be clarified to take away buildup and different issues that present up within the hair (like drugs). Skip on the conditioner, which interferes with the perm answer.

Towel dry the hair; when damp, the hair must be wrapped with perm rods, utilizing sections which can be the identical size and width because the perm rod.

Likewise, the width of the perm rod will dictate how large the curls shall be.

When all hair has been wrapped into perm rods, perm answer must be utilized to every rod individually. As soon as the hair has been totally saturated, let it course of for the period of time listed on the field (sometimes round 20 minutes).

Perm options work by breaking down the disulfide bonds in your hair (the proteins that give your hair form).

As soon as the hair has been absolutely processed, the perm answer must be utterly rinsed out, and the hair must be blotted with a towel till barely damp.

At this level, a neutralizer is utilized to every perm rod; this rebuilds the disulfide bonds within the new form of the perm rod. Let it sit there for five minutes earlier than eradicating the perm rods and rinsing.

Voila! Now you will have curly hair!


FAQ Icon
What’s hair concept?

Hair concept is principally the science of doing hair and studying all of the completely different parts wanted to be a profitable hairstylist. This consists of colour concept, anatomy, chemistry, and even the enterprise aspect of working a salon.

Why is it vital to be taught concept in hairdressing?

It will be unimaginable to be a superb hairstylist with out understanding how issues work. Loads of science goes into hair colour… and even haircuts, curling, and so on. that’s essential to be taught.

Last Ideas

Final Thoughts Icon

Hairstylists need to be taught so many various points of hair by way of concept and expertise. Consequently, there’s much more that goes into hairdressing than one would possibly suppose.

Subsequent time you see your stylist, don’t overlook to understand how a lot work they do to maintain you wanting your greatest!

Till subsequent time,


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