Science saves art. ‘A conservator borrows techniques from the life sciences to care for aging masterpieces. As a young art conservator at the Winterthur museum near Wilmington, Del., Richard Wolbers was assigned an early 19th century painting that needed cleaning. It was Jacob Eichholtz’s portrait of Ann Ross Hopkins, grand-daughter of George Ross, one of the Pennsylvania signers of the Declaration of Independence. The oil paint had been covered with a coating of varnish, and applications of linseed oil had dulled the appearance of the portrait. Having trained as a biochemist at the University of California, San Diego before studying art conservation, Wolbers decided to apply a lipase enzyme to help break down the layer of oil. “It worked like magic,” said Wolbers, now 56 and an associate professor and coordinator of science at the University of Delaware’s conservation program at Winterthur.’
Proteomics of proteins in paintings. ‘Two words that rarely come up in the same conversation are proteomics and painting, unless you are a devotee of the Canadian artist Jacques Deshaies, who has been inspired by the three-dimensional structures of proteins, as well as DNA. His work has graced the covers of scientific journals such as Nature Reviews Genetics and The Scientist. Any other connection may seem far-fetched but proteomics has just been ushered into the world of art restoration.
Artists have been using proteins for several millennia, even though they did not know it at the time. The ancient Greeks and Egyptians painted with a medium known as tempera, which was based on a proteinaceous binder to which the pigments were added. Egg yolk was the most popular binder but casein (from milk), gelatine (from collagen extracted from animal bones and cartilage) and albumin were also used. In the 16th Century, the tempera technique began to be superseded by oil painting and suffered a sharp decrease in popularity, although it remains a recognised, if not dominant practice today.
For art restorers, knowledge of the precise nature of the binders is essential if they are to effect the best repairs. In this sense, modern works have the advantage over their older counterparts because the artist will probably be able to recall the type of binder that was used. For older paintings, this luxury is only a dream, so analytical science is brought into play: identifying the proteins on the canvas will show whether the binder was egg yolk or casein, for instance.’