One way in which scientists define skin type is according to how it responds to exposure to the sun.
    The system of classifying skin according to its type, shown in the table above, was developed on a two-factor basis: hair color and the ability to tan. Classification under this system also indicates the people who are especially prone to develop skin cancer. The six-point scale is based on the answers people give when questioned about how they react to sun exposure.
    Individuals who are types I and II have skin more likely to burn and have difficulty developing a tan. It is also these people who are at highest risk for the development of skin cancer. During the last two centuries or so,

many people of this type have moved to sunny climates like those of Australia and South Africa and are now at a much higher risk of developing skin cancer than if they had stayed in Europe.

Skin type descriptions

Another way of classifying skin types becomes evident when people are asked to describe how they view their skins. For practical rather than necessarily scientific proposes, they will often describe their skin type as either normal, dry, greasy or mixed.
    In the next part of this chapter we discuss each of these descriptions in turn.