Egg tempera, one of the oldest known painting mediums, has been found in ancient Rome, Greece, Egypt and India. The painting method reached a height of popularity in the Middle Ages and during the rise of the Renaissance. As painting with oil became more common, the use of egg tempera slowly faded away. In the 19th and 20th centuries, the ancient methods were rediscovered. Egg tempera experienced a revival as more and more artists began painting with it again.
Egg tempera uses three simple ingredients:
Typically, the egg yolk is separated from the egg white.
Then, the yolk is punctured to remove the yolk from it’s protective casing.
Pigment is then mixed with water to form a paste. This paste is mixed with egg yolk and a little water. Because egg yolk is perishable, the paint needs to be made fresh almost daily.
The painting surface, made of hardboard or solid wood, is coated with many layers of traditional gesso. Unlike modern acrylic gesso, traditional gesso is made of 100% collagen glue (known as rabbit skin glue), chalk (calcium carbonate) or gypsum (calcium sulfate) and titanium white pigment. The gesso is also made and applied by hand and then sanded to a smooth finish.
Paint is applied in very thin layers that quickly dry to the touch. Each coat of underpainting glows through the subsequent layers, creating a luminous result. The yellow pigment of the yolk (lutein) bleaches out when exposed to light and the water content of the yolk evaporates. Over time, the egg yolk cures and creates a hard surface.
While the layers dry quickly, dozens and even hundreds of layers of paint can be applied to a single painting. Often, a single painting will take weeks, months or even years to be finished. Over a period of months, the paint will continue to cure. After curing, the painting is either varnished or polished to a shine.
Many egg tempera paintings have survived over the centuries and are on display throughout the world. Because they do not contain oil, the paintings do not darken over time, and they appear to have been freshly painted.
With proper care (hanging a painting out of direct light), egg tempera paintings will maintain their beauty and continue to inspire others for centuries to come.