Egg Tempera Medium is a medium for tempera paint made of egg yolk with gum arabic. It can be mixed directly with pigments, water-based pigment pastes, and tempera pastes. The resin content of gum arabic increases the transparency and glossiness compared to the egg yolk by itself as a medium, and it gives a matte yet moist texture to the painting. The basic rule is to use an equal volume when you mix it with pigments.