tempera -
A medium used to bind pigments in painting, as well as the associated artistic techniques.
Wikipedia
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 first centuries AD still exist.
