The Lightening Curve – Includes Free PDF
Along with the colour wheel, the lightening curve is an essential tool that the best colourists in the world refer to when formulating colour services. The lightening curve provides a colourist with a visual representation of the underlying pigments of each depth of hair colour.
How Hair Colour Pigments are Produced
Natural hair colour pigments are produced in the germinal matrix of the hair bulb.
Within the germinal matrix of each hair shaft are colour pigment producing factories called melanocytes. The melanocytes produce melanosomes that contain the hair’s natural hair colour pigments, melanin. The melanosomes pass through tentacle-like structures into newly produced hair as it grows, providing each hair shaft with its natural colour. Melanocytes produce two types of melanin:
Pheomelanin – red/yellow colour
Eumelanin – brown/black colour
Typically, the less brown/black pigment that is present, the lighter the hair is and the more brown/black pigment that’s present, the darker the hair is. The levels of melanin in the hair can vary over time causing the hair to change colour at different points in a person’s life. It is also possible to have follicles on the same head producing different amounts of melanin.
White or colourless hair occurs because the melanocytes are producing melanosomes which no longer contain melanin.
The Lightening Curve
It is important that you refer to the lightening curve when formulating for client colour services because it provides you with a reference of the amounts of underlying Pheomelanin and Eumelanin that can be found at each depth. This melanin gets exposed when you lighten hair and must be replaced when you darken hair.
Considering the Lightening Curve when Lightening Hair
To provide your clients with successful lightening services it is crucial that you take into consideration the underlying pigments, more commonly known as underlying warmth, at your target depth. For example, your client is a natural depth of 6/0 and wants to achieve a neutral depth of a 9/0. You refer to your lightening curve and identify that you will expose the underlying warmth of pale yellow as you lighten the hair to the target depth.
In order to achieve the neutral very light blonde your client wants you will need to formulate your target shade with the complementary colour of yellow. You refer to your colour wheel and identify that the complementary colour of yellow is violet. You formulate a 9/6 (violet with your colour house) with the correct level of hydrogen peroxide to achieve three levels of lift. The violet neutralises the underlying warmth as the hair lifts and you achieve the neutral blonde your client was looking for. Happy Days!
MHD’s popular colouring instructor, Charmain Piche demonstrates the results that can be achieved by formulating to neutralise the underlying warmth in our online step-by-step hair colouring video Basic Tint Application Light. In this colouring tutorial Charmaine formulates to achieve a light base with brilliant cool summer blonde tones:
Jo McKay also demonstrates how to neutralise underlying warmth at a darker depth in her Colour Melt step-by-step video. By neutralising the underlying warmth through the upper sections, Jo achieves a beautiful amalgamation of oyster and caramel tones.
Considering the Lightening Curve when Darkening Hair
It is equally important to consider the underlying warmth at your target depth when darkening previously lightened hair. Failing to do so results in the warm pigments of your target shade being absorbed into the hair shaft and the cool pigments being reflected out. You will end up with a cool muddy result in which the hair can look green or khaki.
In order to prevent an unfavourable result when darkening previously lightened hair you must replace the underlying warmth that would exist naturally at your target depth. This process is called pre-pigmentation.
For example, if your client is pre-lightened to a depth of 10/0 and wishes to return to a natural brunette shade at a depth of a 6/0 you will need to replace the orange (copper) underlying warmth before applying your target colour formulation.
MHD Instructor Tracey Sajno demonstrates pre-pigmentation beautifully. She provides a commercial salon friendly pre-pigmentation service to achieve a darker depth that enhances her veiled slicing technique.
Charmaine Piche also demonstrates a salon friendly pre-pigmentation service to achieve a beautiful two-toned blonde application. Charmaine pre-pigments previous highlights in the lower section of the back before applying a new target shade to achieve depth underneath her highlighted upper sections.
Referring to the science of your lightening curve and underlying warmth when lightening and darkening hair should be a crucial step in your colour formulation process. Download our free Lightening Curve PDF and place on the wall in your technical area as a quick reference for all your colour services.
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