Normal pigmentation caused by increased melanin synthesis can appear not only on all parts of the mucosa but also on the skin and as any number of different manifestations. It shows clinically asymptomatic areas that range from brown to black in colour and indicate single or multiple lesions of varying size. In areas of pressure and friction, the pigmentation becomes more prominent and it normally increases with aging. Moreover, areas of dark discoloration are very common on dark-skinned patients. A detailed list of all the variations of oral pigmentation can be found in the chapter entitled 'pigments and colour changes' of this atlas.