Source: Wikimedia Commons
Tempera is a term applied to any paint in which the pigment is dissolved in water and mixed (tempered) with an organic gum or glue, and paintings done in this medium.[1] Sometimes called distemper in English,[2][a]Tempera is the Italian for “distemper”.[3] the term is now generally confined to the most common form of the medium, egg tempera, in which the binding agent is egg yolk.[1] Tempera has been in use since ancient times, and has been found on Ancient Egyptian sarcophagus decorations.[4]
Tempera was commonly used for painting wooden panels during the medieval period, but had been largely superseded by oil painting by the early 16th century. Although the colours of tempera are more vivid and luminous than oils, their restricted colour range ruled out the more naturalistic effects available with oil paints.[1]