Scientists Find Unexpected Ingredients in Ancient Egyptian Paint

Ancient Egypt is a gold mine of humanity’s best artwork from antiquity. Remarkably, many artifacts from this era retain their vibrant colors to this day—and scientists now understand how this was possible.

An international team of conservators, historians, and archaeologists conducted a detailed analysis of paint binders and adhesives in painted artifacts from between 1425 BCE and 40 CE. In a Science Advances paper published today , the researchers report not just the importance of glue in the preservation of Egyptian art, but also a previously unknown dependence on plant ingredients. For the study, the team analyzed 28 paint and adhesive samples taken from 14 different pieces of artwork held by the Egyptian collections in major museums. The discovery sheds new light on how, for Egyptian artists, their choice of materials held religious and symbolic value.

“Our finding challenges long-held assumptions about ancient painting techniques and opens new windows into workshop practices, ancient trade, and the materials’ religious and symbolic meaning,” Clara Granzotto , the study’s first author and a conservation scientist at the Art Institute of Chicago, told Gizmodo.

According to the paper, researchers were already aware that ancient Egyptians used paint binders and adhesives, which were likely a byproduct of butchery. Ancient artisans obtained glue by boiling animal bones and connective tissues. That said, this was primarily based on visual observations, and it was only relatively recent that scientists began to really investigate the chemical and biological origins of artistic materials.

Still, it was clear that the adhesives did wonders for the artisans of ancient Egypt. For the latest study, Granzotto and colleagues studied paint layers applied onto wooden coffins, fragments of tombs, cartonnage , and architectural elements made of limestone. The adhesives were also actively used to hold things together, like the lid of a wooden coffin. Being in such close proximity to this artwork, it was evident “how accurate and detailed the paint is,” Granzotto said. “It’s simply incredible.”

There’s an obvious obstacle when it comes to studying ancient artifacts, many of which are more than 2,000 years old. They are very, very fragile. That makes it even more impressive that the organic material on Egyptian artworks has survived, but in discussing the project with museums, Granzotto and colleagues had to find a technique that would minimize the harm to these precious artifacts.

They opted for proteomics , a technique in which tiny samples of ancient proteins are used to extract a surprisingly large dataset of information. To gather these samples, the team studied the artwork under microscopes and took physical samples using surgical needles and blades. They also excluded particles that might have come from archaeological or conservation work in the past.

The project’s primary focus was to provide “solid analytical evidence” for the use of organic materials in paint binders and adhesives of ancient Egypt, which the team’s findings did provide. Among the plants and plant-based products detected were cereals and pollen allergens.