There is More to Mixing Hair Colour Than You Might Think
Mixing hair colour can be perceived as a quick and easy step but in actual fact this process needs a lot of thought and consideration.
Hair colouring products should always be prepared after a client analysis and with due consideration of hair care procedures. For example, applying a dye to fine hair will have a different effect to applying the same dye on to thick hair. If the same amount of dye intended for normal hair is applied to fine hair, the end result will be a darker shade as the same number of developed pigments will be concentrated into a smaller area.
Similarly, other aspects unique to an individual need to be taken into account, such as porosity, percentage of white hair in mature hair, as well as the client’s own aspirations of the final colour. Exact preparation of hair colouring products is brand specific, however there are general guidelines common to all.
When hydrogen peroxide and an alkali (normally ammonia) are mixed together an oxidative reaction starts immediately; both permanent and demi-permanent colours are oxidative. This process has a limited reaction time, hence it is important to apply newly mixed colours as soon as possible. Failure to do this can prevent the target colour from being achieved due to insufficient lift or insufficient deposit and development of pigments.
Plant Based Colours
Henna and other plant ingredients should be mixed with hot water to create a thick paste, once applied they should be left for up to one hour depending on the hair type. Different ingredients are often added to henna to alter the tonal qualities, for example, camomile, walnut, indigo, red wine or tea.- Semi-Permanent Colours
These are ready for immediate application. Mixing colours together is normally possible, as the process is not oxidative. - Demi-Permanent Colours
Demi-permanent colours belong to a product group that fits between permanent and semi-permanent colour.
Demi-permanent colours will contain a mix of developed direct pigments and undeveloped para-dyes. The dye precursors are oxidative and therefore need to react with oxygen in order to develop, because of this, demi-permanent colours need to be mixed with a weak hydrogen peroxide solution.
Because dye precursors are used in this product a skin test should be taken. - Permanent Colour
Permanent oxidative colours are not ready to use and need to be mixed with hydrogen peroxide before being applied to the hair.
Oxidative colours are always mixed with peroxide, normally with equal amounts of peroxide to colour cream. Chemicals should always be prepared in a non-metallic bowl as metal reacts unfavourably with peroxide. Mix together with a plastic applicator brush or similar and allow to stand briefly in order for the solution to stabilise.
Use of scales is highly recommended, preferably an electronic model that allows the user to reset the reading as additional ingredients are added to the recipe. Bleaches are also mixed in a similar way, though may be cream or powder based.
Tubes of colour are often marked to show how much of the chemical has been squeezed out; hydrogen peroxide, however, comes in various pre-mixed strengths allowing more control over the intensity of effect on the hair. The strength of hydrogen peroxide is measured either as a percentage or as volume; for example 3% is equivalent to 10 volume.
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