The typological term normal type (in German: Normaltyp) has been coined by Ferdinand Tönnies (1855-1936, German sociologist). It should not be confused with Max Weber’s term ideal type (in German Idealtyp).
Tönnies drew a sharp line between the realm of conceptuality (of sociological terms, including "normal types") and the realm of reality (of social action). The first has to be treated axiomatically and in a deductive way (Pure Sociology), the second, empirically and in an inductive way (Applied Sociology). Following Tönnies, reality (the second realm) cannot be explained without concepts, which belong to the first realm, or else you will fail, because you try to define x by something derived from x.
Tönnies' Normaltyp was hitting at the German sociologist Max Weber, whose "ideal type" (Idealtyp) was coined as an "accentuation" of certain elements of a real social process, which is under sociological (or historical) scrutiny. Nevertheless, Weber's term survived in the sociological community, since his Idealtyp helped to understand social forces, and for him "sociology" had both to explain and to understand things - a daring combination, but successful in the eyes of many sociologists.
It should not be confused with Max Weber’s term ideal type (in German Idealtyp).
Tönnies drew a sharp line between the realm of conceptuality (of sociological terms, including "normaltypes") and the realm of reality (of social action).
This will fit the majority of combination skin types except for a small percentage that may have symptoms such as a pimply forehead or cheeks that are dry where all else is normal.
Normal skin is a mix between oily and all skin types, but since it inhibits the same characteristics of oily skin, normal/oily are joined together in the same category.
Normal skin types have regular deep circulation and its secretions of natural oil are sufficient to insure a good humidity rate without obstructing the pores.