The invisible secrets of historical paintings

Any observer of an artwork inevitably wonders: who made it, and when? While authorship is complex to determine, radiocarbon (¹⁴C) dating can help date the object—though sampling is delicate due to the uniqueness of artworks. Until now, only the substrate of an artwork has been dated, due to sample size constraints. Natural organic colourants, widespread in cultural heritage, are carbon-rich, short-lived, and reflect the ¹⁴C signature of the organism’s growth, making them ideal candidates for dating. My research focuses on these colourants, deliberately chosen by artists and directly tied to an object’s creation, to demonstrate their potential as proxies for determining the age of artworks through radiocarbon analysis.

The Huaca Pintada is a small pyramidal mound located in the north coast of Peru where a hundred years ago, a group of looters accidentally uncovered a spectacular polychrome mural depicting ancient Moche warriors and a main deity. Regrettably, it is said that the same looters destroyed this fabulous finding after being prohibited from further excavating the site. This talk will explore the recent rediscovery of this mysterious painting—now known to be over a thousand years old—thanks to the efforts of a Swiss-Peruvian archaeological team. It will also consider the broader implications of this find for research in Pre-Columbian studies.