Cracking the Code: The Role of Eggs in Old Master Paintings

A new study published in the journal Nature Communications has found that Old Masters such as Leonardo da Vinci, Sandro Botticelli, and Rembrandt may have used proteins, especially egg yolk, in their oil paintings. The study sheds light on the technical knowledge of the Old Masters and the way they prepared their paints. The researchers recreated the process of paint-making by using four ingredients — egg yolk, distilled water, linseed oil, and pigment — to mix two historically popular and significant colors, lead white and ultramarine blue. The chemical reactions between the oil, the pigment, and the proteins in the yolk directly affect the paint's behavior and viscosity.