Cosmetology · Haircoloring Principles

Permanent haircolor most often works within which layer of the hair?

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Correct answer

The cortex (after the cuticle is opened)

A The cuticle only
B The medulla only
C The scalp
D The cortex (after the cuticle is opened)

Why this is the answer

Permanent haircolor works mainly within the cortex of the hair. The product (typically with a developer) raises the cuticle so the color can penetrate into the cortex, where it develops and becomes trapped, producing long-lasting color. This is why permanent color is a chemical change and grows out rather than washing away quickly. Temporary and some semi-permanent colors deposit more on the surface/cuticle. Connecting where color works (the cortex) to the structure of the hair shaft is standard color theory on the exam.

Source: Hair Care — Where Color Works

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About this topic: Haircoloring Principles

Haircoloring principles cover the colour wheel and levels, the categories of haircolour (temporary to permanent), developers and volumes, lightening, patch tests and formulation. The chemistry of oxidative colour is tested every time. This is one of 8 Hair Care questions on haircoloring principles, each with a full explanation on a single study page.

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Permanent haircolor most often works within which layer of the hair?

Why this is the answer

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About this topic: Haircoloring Principles

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