The egg tempera painting technique was the main method of applying paint to panel throughout the early Renaissance. As the title suggests the pigment is mixed with egg, using the white of the egg or the yolk results in different effects, the mixture is fast drying and permanent.
Tempera has been discovered on early Egyptian decorations and the painting technique was also used throughout the Byzantine period.
Typically a wooden panel was prepared by covering the surface with layers of gesso (made with gypsum mixed with animal glue and worked into a thick paste).
A rough layer was applied, the gesso grosso, the panel would then be finished in a smooth covering of gesso, the gesso sottile.
Any joints or knots in the wood had to be sealed with strips of linen or sized to ensure that the gypsum adhered to the surface of the panel. The final gesso surface is then polished to the smooth, brilliant white consistency required for the application of the paint.