Tempera is made by mixing powdered pigments with water-soluble materials, like water or albumen (egg yolks), or a solidifying base such as fig sap or thin glue.
Tempera dries very quickly. Thus, it is applied with small, quick brushstrokes to ultrasmooth surfaces.
The advantage of using tempera as a painting medium is that clear, intense colors are produced. These colors are not subject to oxidation and as a result do not lose their integrity over time as oils do.
Minerals, wood, plants and different types of clay are the source of the pigments originally used in pigments. The three basic types of pigments are chlorophylls (greens), carotenoids (reds, oranges) and phycobilins (blue).
The modern term "tempera" refers to poster paint, which is a form of gouache. Gouache is a type of opaque watercolor.
Modern tempera comes in a powdered form and in dry cakes that are mixed with water and used in the same manner as watercolor cakes. The higher the pigment content of the tempera paint, the more color-stable it will be.