Egg yolks are my medium.
I have used all sorts of paints in my life – from finger paints and mud to house paint to artist’s oil paints. I am currently using eggs.
The objective of a medium is to adhere pigment to a surface. Eggs are sticky, especially when dried. The longer they are dry, the more stubborn an egg is.
Each form of paint has pros and cons and preferred surfaces. Eggs are a bit brittle when dry so they require a stiff surface. A panel, a piece of wood, or a wall are the classic surfaces. For longevity, one needs a porous surface that will suck in and secure the yolk. The classic ground is gesso. Traditional gesso is made of hide glue and chalk, optional is addition of marble dust or white pigment. Egg paints are also used on plaster walls.
Egg tempera -as egg paints are commonly called- is a fast drying paint that cures to a very rigid permanent, subdued sheen. Egg yolks are mixed with water to a painterly consistency to use as the medium. Then, one adds in pigments. Pigments are from a variety of substances, many are ground earth or minerals. Some, more ephemeral, are plant matter. These days we also have manufactured pigments. Basically, pigments are finely ground up pretty colors.
The names are familiar: cadmium reds, yellows, oranges, titanium, zinc, carbon, ochres, umbers, earths, chromes, cobalts. Many have long histories in artist use. Each a story of their own when they entered the artist’s palette. Some cheap as dirt, some precious as rare jewels.
The pigments is mixed with water to form a paste and then with the egg yolk for permanence.