Painting masters like Leonardo da Vinci, Sandro Botticelli and Rembrandt may have used proteins , especially proteins from egg yolks , in their oil paintings, according to a new study.
According to CNN, trace amounts of protein residue have long been found in classical oil paintings, although they are often attributed to contamination.
A new study published March 28 in the journal Nature Communications suggests that the inclusion of this protein in oil paintings may be intentional. This study sheds light on the drawing techniques knowledge of the masters (Old Masters generation) of the most talented European painters of the 16th, 17th or early 18th centuries and how they prepared paint to draw.
“There are very few written sources on this issue and no previous scientific work to support this,” said study author Ophélie Ranquet of the Institute of Mechanics and Mechanical Process Engineering at the Karlsruhe Institute of Technology in Germany. research on this topic in such depth. Our results show that even with a very small amount of egg yolk, you can achieve amazing changes in properties in oil paints, demonstrating how beneficial it can be for painters”.
As it turns out, simply adding a little egg yolk to your compositions can have lasting effects, not just aesthetics.
Illustration: Getty Images
Compared to the kind that the ancient Egyptians concocted and called a glue color (which combines egg yolks with gouache and water), oil paints produce a darker color, allowing for a very smooth transition and drying quickly. much more, so can be used within a few days after mixing. However, oil paints (using linseed oil or safflower oil instead of water) also have disadvantages, such as being more prone to darkening and damage from light exposure.
Because painting was a handmade and experimental process, it is possible that the painters added egg yolks to the new paint that first appeared in the 7th century in Central Asia before spreading to the North. Europe during the Middle Ages and Italy during the Renaissance.
In the above study, the researchers recreated the paint making process using four ingredients: egg yolks, distilled water, linseed oil, and pigments to mix two common and important colors, lead white and lead white. blue.
“Adding egg yolks is beneficial because it can dramatically modulate the properties of these paints,” says Ms Ranquet. For example, paint with egg yolks contains oxidants, so it will oxidize more slowly.
The chemical reactions between oils, pigments and proteins in the yolk directly affect the activity and viscosity of the paint. For example, lead white is quite sensitive to moisture, but coating it with a protein layer makes it much more resistant to moisture, making the paint fairly easy to apply.
“On the other hand, if you want something stiffer without having to add a lot of gouache, then with a little bit of egg yolk you can create a high-gloss finish,” says Ms. Ranquet.
For centuries, artists have wanted to use less pigments because certain pigments – such as lapis lazuli, which are used to create ultramarine blue – are more expensive than gold, according to Ms. Ranquet.
“The Madonna of the Carnation” at Alte Pinakothek in Munich, Germany is one of Leonardo da Vinci’s earliest paintings. Wrinkles of oil paint are clearly visible on the face. (Image: Getty Images).
Direct evidence of the influence of egg yolks in oil paints can be found in Leonardo da Vinci ‘s “Madonna of the Carnation” . This is one of the paintings observed during the research and is on display at the Alte Pinakothek in Munich, Germany. The work shows obvious wrinkles on the faces of Mary and the child.
“Oil paint starts to dry from the surface down, that’s why it gets wrinkled,” Ms. Ranquet describes.
One reason for paint to wrinkle can be an insufficient amount of pigment in the paint, and research has shown that this can be avoided by adding egg yolks: “That’s pretty amazing because you get the same amount pigment in my paint, but thanks to the egg yolk, everything changes.”
Since wrinkles appear within a few days, it is possible that Leonardo and other artists may have known this as well as the beneficial properties of adding egg yolks to oil paints, including resistance to moisture. “Madonna of Carnation” is one of Leonardo’s earliest paintings, painted at a time when he was probably still trying to master the then popular new oil painting medium.
Another painting observed during the study was Botticelli’s “The Lamentation Over the Dead Christ” , also on display at the Alte Pinakothek. The work was mainly painted with glue colors, but oil paint was used for the background and some secondary elements.
Ms Ranquet said: “We knew that some parts of the painting showed the typical brushstrokes of oil paintings, but we did detect proteins. Because there are very few proteins and they are difficult to detect, this can be mistaken for contamination. In the studios, the artists used many different things, and maybe the eggs just came out of the glue color.”
However, since adding egg yolks creates such a wonderful effect on oil paints, the presence of protein in the work could be a sign of intentional use. Ms. Ranquet hopes that these early findings can draw more attention and curiosity to this little-studied topic.
Maria Perla Colombini, Professor of Analytical Chemistry at the University of Pisa in Italy, agrees with the study: “This interesting paper offers a new scenario for understanding old drawing techniques… This new knowledge does not not only contributes to better preservation and preservation of works of art, but also helps to better understand the history of art”.