Editing Tempera (section)

===Egg tempera===
The most common form of classical tempera painting is "egg tempera". For this form most often only the contents of the [[egg yolk]] is used. The [[Egg white|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). The egg yolk is diluted with water and used with pigment. Some kind of remedy is always added in different proportions. One recipe uses vinegar as a preservative, but only in small quantities. A few drops of vinegar will keep the solution for a week. Some egg tempera schools use different mixtures of egg yolk and water, usually the ratio of yolk to water is 1:3; other recipes offer white wine (1 part yolk, 2 parts wine).

Powdered pigment, or pigment that has been ground in distilled water, is placed onto a palette or bowl and mixed with a roughly equal volume of the binder.<ref>Mayer, Ralph, 1976. ''The Artist's Handbook of Materials and Techniques'' (3rd ed.). New York: Viking Penguin Inc., p. 228.</ref> Some pigments require slightly more binder, some require less.

When used to paint icons on church walls, liquid [[myrrh]] is sometimes added to the mixture to give the paint a pleasing odor, particularly as worshippers may find the egg tempera somewhat pungent for quite some time after completion. 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 a different effect. Other additives such as oil and [[wax emulsion]]s can modify the medium. Egg tempera is not a flexible paint and requires stiff boards; painting on [[canvas]] will cause cracks to form and chips of paint to fall off.

Egg tempera paint should be cured for at least 3 months, up to 6 months. The surface is susceptible to scratches during the curing process, but will become much more durable after curing. Egg tempera paintings are not normally framed behind glass, as the glass can trap moisture and lead to the growth of mold.<ref>{{Cite web |title=Egg Tempera Misconceptions - Egg Tempera Forums |url=https://www.eggtempera.com/forum-archive/showthread.php@p=6726.html |access-date=2023-01-29 |website=www.eggtempera.com}}</ref>