Telling the Story of Art Using Mobile Raman Technology

Raman spectroscopy has evolved as an effective tool for helping scientists analyze the composition of a variety of art. Anastasia Rousaki is one of those scientists.

Rousaki, who is a senior postdoctoral researcher at Ghent University in Belgium, spoke about the Raman techniques her team used to analyze art from a variety of periods during a session at SciX in Sparks, Nevada on October 10. She outlined three instances where the team used mobile non-invasive Raman spectroscopy to test the composition of works of art from the prehistoric period, the late 19th to early 20th century, and the 21st century.

The first example Rousaki shared is an analysis of rock art paintings in 16 open-air shelters in Patagonia. These prehistoric rock art paintings were created by hunter-gatherer communities, and the team wanted to develop a more robust understanding of the palette ancient humans used to create these murals.

“We had a dual question from the local archaeologists,” she said. “First, we needed to know the materiality of the painting. What is the palette of the local hunter gatherer population. We needed to actually see the preservation state of the painting.”

Using a dual Raman laser system, the team was able to determine that the hunter gatherers used typical pigments for the time. Information that, Rousaki added, would “help the local community and local archaeologists to understand these paintings and preserve them in a better way.” (Patagonian prehistoric rock art project: acknowledgements to FWO (project K204416N), Ghent University (through GOA), Consejo Nacional de Investigaciones Científicas y Técnicas through PIP 365 and the entire team from Argentina and Patagonia(CONICET, Facultad de Ingeniería-Universidad de Buenos Aires and Comisión Nacional de Energía Atómica, Angentina, Museo de la Patagonia).

Next, Rousaki outlined work that her team had done in Athens, analyzing Greek painters from the Munich School, which were prevalent during the19th to early 20th century. Using Raman mapping technology (Virsa™ Raman analyser, Andrew J. King, Renishaw) , the team set up at the National Gallery-Alexandros Soutsos Museum in Athens. The challenge, she said, was completing this work during working hours at the museum, where vibrations from visitors walking around the museum could interrupt their analysis.

“We were able to acquire the Raman distribution of pigments in different zones in the paintings inside the museum,” she said.

The team looked at a variety of paintings, including Nikiforos Lytras’ “Antigone and Polyneices.” This painting, she said, proved difficult to analyze with Raman technology because of heavy layers of degraded varnish.

“The varnish was degraded and quite thick, so we couldn’t read the paint layer at all,” she said.

Rousaki’s team also compared the pigments used in paintings by Andreas Kriezis and Francesco Pige. Pige and Kriezis present strong similarities in their painting style. The team tried to record their painting technique and their differences by detecting the painting materials. Rousaki also looked at several works of art by Symeon Savvidis.

“We wanted to understand the palette and if it used the same materials between the three paintings,” she said. (Greek painters from the Munich School project: this campaign is embedded in the postdoctoral research of Eleni Kouloumpi, National Gallery-Alexandros Soutsos Museum. Acknowledgements to: Metrohm, Renishaw, Ghent University (BOF), FWO (grant number: K217723N), University of Évora (HERCULES Lab and IN2PAST Associate Lab - City University of Macau Chair in Sustainable Heritage) and National Gallery-Alexandros Soutsos Museum.

Rousaki’s team traveled to Reggio Emilia, Italy to analyze 21st century murals. The researchers analyzed the murals using different Raman systems, and were able analyze the degradation pathways that impact the street art murals. (Street art murals project: this work was supported by the European project “Conservation of Art in Public Spaces” (CAPuS) (Call EAC/A03/2016), Project N° 588082-EPP-A-2017-1-IT-EPPKA2-KA). Acknowledgements to Ghent University and FWO (project number: 12X1919N). Collaboration with Danilo Bersani, Università di Parma, Italy and the entire team involved).

Advancements in Raman spectroscopy have allowed Rousaki and her team to use non-invasive techniques to study works of art where they are (in situ). An analysis tool that will be useful in art history for years to come.

“More projects are done with new instruments on site or without taking a sample from the painting,” she said.