Tempera. Tempera, also known as egg tempera, is a permanent, fast-drying painting medium consisting of pigments mixed with a water-soluble binder medium, usually glutinous material such as egg yolk. Tempera also refers to the paintings done in this medium. Tempera paintings are very long-lasting, and examples from the first century AD still exist. Egg tempera was a primary method of painting until after 1500 when it was superseded by oil painting. A paint consisting of pigment and binder commonly used in the United States as poster paint is also often referred to as tempera paint, although the binders in this paint are different from traditional tempera paint. The term tempera is derived from the Italian dipingere a tempera, from the Late Latin distemperare. A 1367 tempera on wood by Niccolò Semitecolo. Tempera painting has been found on early Egyptian sarcophagus decorations. Many of the Fayum mummy portraits use tempera, sometimes in combination with encaustic painting with melted wax, the alternative painting technique in the ancient world. It was also used for the murals of the 3rd century Dura-Europos synagogue. A related technique has been used also in ancient and early medieval paintings found in several caves and rock-cut temples of India. High-quality art with the help of tempera was created in Bagh Caves between the late 4th and 10th centuries and in the 7th century in Ravan Chhaya rock shelter, Odisha. The art technique was known from the classical world, where it appears to have taken over from encaustic painting and was the main medium used for panel painting and illuminated manuscripts in the Byzantine world and Medieval and Early Renaissance Europe. Tempera painting was the primary panel painting medium for nearly every painter in the European Medieval and Early renaissance period up to 1500. For example, most surviving panel paintings attributed to Michelangelo are executed in egg tempera, an exception being his Doni Tondo which uses both tempera and oil paint. Oil paint, which may have originated in Afghanistan between the 5th and 9th centuries and migrated westward in the Middle Ages eventually superseded tempera. Oil replaced tempera as the principal medium used for creating artwork during the 15th century in Early Netherlandish painting in northern Europe. Around 1500, oil paint replaced tempera in Italy. In the 19th and 20th centuries, there were intermittent revivals of tempera technique in Western art, among the Pre-Raphaelites, Social Realists, and others. Tempera painting continues to be used in Greece and Russia where it is the traditional medium for Orthodox icons. Tempera is traditionally created by hand-grinding dry powdered pigments into a binding agent or medium, such as egg yolk, milk and a variety of plant gums. 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 white of the egg and the membrane of the yolk are discarded. 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. 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. 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 emulsions 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.
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