The color green is used as an under layer when painting faces.
Explanation:
<em>Terra Verte</em>is the designation applied to a set of pigments that owe their color to green clay minerals such as celadonite, glauconite and chlorite.
In the Middle Ages it was widely used in tempera painting, especially in a layer underlying the carnation layer. Cennino Cennini describes this use as follows: '<em>pick up a little green soil and a little lead white, well mixed; apply two layers under the face, under the hands, under the feet and under the carnation areas</em>'; When applying the pink colored layers, '<em>keep in mind that in wood painting more layers have to be applied than in mural painting; but not many more, so that some of the green that is already under the carnation areas is still visible</em> »
Tempera is traditionally created by hand-grinding dry powdered pigments into a binding agent or medium, such as egg yolk, milk (in the form of casein) and a variety of plant gums.
