Tempera, also known as egg tempera, is a permanent, fast-drying painting medium consisting of colored pigment mixed with a water-soluble binder medium (usually a glutinous material such as egg yolk or some other size). Tempera also refers to the paintings done in this medium. Tempera paintings are very long lasting, and examples from the 1st centuries AD still exist. Egg tempera was a primary method of painting until after 1500 when it was superseded by the invention of oil painting. A paint consisting of pigment and glue size commonly used in the United States as poster paint is also often referred to as “tempera paint,” although the binders and sizes in this paint are different from traditional tempera paint.
The most common form of classical tempera painting is “egg tempera”. For this form most often only the contents of theegg yolk is used. The white of the egg and the membrane of the yolk are discarded (the membrane of the yolk is dangled over a receptacle and punctured to drain off the liquid inside). Egg yolk is never used by itself with pigment; it dries almost immediately and crackles when it is dry. Some agent is always added, in variable proportions. One recipe calls for vinegar (1:1 proportion to egg yolk by volume); other recipes suggest white wine (1 part yolk, 2 parts wine). Some schools of egg tempera use various mixtures of egg yolk and water.
The paint mixture has to be constantly adjusted to maintain a balance between a “greasy” and “watery” consistency by adjusting the amount of water and yolk. As tempera dries, the artist will add more water to preserve the consistency and to balance the thickening of the yolk on contact with air. Once prepared, the paint cannot be stored. Egg tempera is water-resistant, but not waterproof.
Different preparations use the egg white or the whole egg for different effect. Other additives such as oil and wax emulsions can modify the medium.
Egg tempera is not a flexible paint and requires stiff boards; painting on canvas will cause crackle and pieces of paint to fall off.
uses a style of painting that makes awesome use of tempera’s thick paste like qualities.