Mass spectrometry-based proteomics is a sensitive technique that characterizes all proteins in a sample, requiring less material than other methods. In 2023, it revealed beer byproducts as canvas primers in Danish Golden Age art, and earlier this year, it identified proteins from Renaissance fingerprints in medical manuals.

For this study, researchers took tiny samples from Egyptian artifacts in Sweden, the UK, and Denmark, dating from 1425 BCE to 400 CE. These included painted wooden coffins, wall painting fragments, a mummy bust, and painted limestone elements. Blank controls and chemical damage analysis ruled out contamination.

Results confirmed ancient Egyptians used cow glue and collagens from sheep, goats, horses, donkeys, and antelope, likely prepared by boiling animal skin and connective tissue. These were found in adhesives, paint, and ground layers, suggesting material choice based on availability.

"No notable correlation was observed between the choice of the animal species/part and the object type, the nature of the application, the color, the chronology, the geographical origin, or the use context (funerary or palatial)," the authors wrote.