In order to understand and appreciate the painting of past centuries we must have knowledge of the pigments used until the end of the eighteenth century. In particular we should know their qualities and properties such as the form of their grains, specific gravity, color strength, opacity, as well as the media used for their application. Finally, we must take into consideration the effect of falling or reflected light on the surface of a painting. The article is divided according to the following categories: 1) properties and mediums of pigments, 2) optical properties of pigments, 3) chromatic strength of the pigments, and 4) the major pigments grouped by color. -- AATA