Oil based tempera

Recipe for oil based tempera
Ingredients: 1 whole egg, 1 tsp. raw linseed oil, 4 drops vinegar
pigment paste (pigment ground with a tiny amount of water or alcohol)

Break the egg and drop the contents into a small clean jar. Add the oil, cap the jar, and shake the contents until they combine completely. Add vinegar as a preservative. Strain the whole mixture through two layers of cheese cloth into a fresh jar. This emulsion produces a paint which can be thinned or diluted with water, and which is slightly less oily than other egg/oil emulsions. Grind pigment paste into the emulsion, using only as much pigment as you need for one painting session.