Hair colouring

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Hair colouring

  1. 1. Hair ColouringHair Colouring is the process of addingcolour to the natural hair colour. It is used todisguise or cover over white hair, or toenhance and change the natural hair colour.Hair ColouringThe natural pigments of hair are found in thecortex; outermost layer of the hair-shaft- thecuticle-that covers and protects the cortex, istranslucent, therefore it allows us to seethrough the hair’s natural colour. Eumelaninis the black and brown pigment, whilephaeomelanin is the pigment responsible forblond and red.Product Available to Dye HairTemporary colour: this type of colour is found mainly in sprays, gels, water rinses and somecolour shampoos. This colour contains large colour molecules which are too large to penetrate thecuticle layer of the hair, and it doesn’t contain ammonia, which is used to open the hair cuticles,allowing the colour molecules to penetrate inside the hair. This type of colour will only last onewash.Semi –permanent colour: this type of colour will last between six to eight washes, depending onthe natural hair colour and the tone of the colour used. With eight shampoos the colour will fade.This type of colour contains a mixture of sizes of coloured molecules, and as it is slightly alkalinethe cuticle scales will open, thus allowing the product to enter the cuticle: the smaller themolecules, the farther they will travel. So as the hair is shampooed each time, the large moleculeswill wash out but the smaller molecules will remain, enabling the colour to last longer.Permanent colours: these tints, also called oxidation dyes, require the addition of hydrogenperoxide, otherwise they will not work. The small colourless molecules within the tint enter thecortex. Once inside, the hydrogen peroxide activates them into joining together to form largecoloured molecules which then become trapped within the cortex. This process can take anythingfrom thirty minutes to sixty minutes, depending on the product that you are using. If this productis taken off too soon, it will become semi-permanent. 1Grazie a tutti i lettori… ☺

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