The Cephalopod’s Syllabus: The Science of Art Restoration

BY MASHA DOLGOFF
University of South Florida Sarasota-Manatee STEM major

Here in Southwest Florida, we’re lucky enough to have vibrant Sealife that includes a couple species of octopuses. These fascinating creatures, belonging to the animal class Cephalapoda, are known for their remarkable intelligence. Their ability to constantly expand their knowledge of their environment has inspired this column.

For the fall session, I’m bringing you impressions gathered during my summer semester abroad in Florence, Italy, where I took an organic Chemistry course. Although Florence is primarily renowned for its art and culture, once I started looking for the way its historical heritage intersected with science, I saw signs of it everywhere.

In chemistry, there is a key principle known as resonance, in which a system incorporates multiple states at once in a hybrid structure. Its uncanny resemblance to the word Renaissance brings to mind the revival of antiquity in the style of artwork that draws flocks of visitors to the city’s galleries every year. Like its near homophone, it seems to describe how Florence exists between two states, its past integrating directly with modern life as everyday bustle happens in front of the more than 600-year-old Cathedral of Santa Maria del Fiore or a basketball tournament held after sunset on the Piazzale Michelangelo overlooking the entire city.

There’s no better arbiter of this precious link than the art restoration professional. Curious about how experts preserve and rehabilitate delicate paintings and architecture from centuries of wear and tear to allow it to inspire new generations, I spoke to Maria Costagliola, a chemistry professor who specializes in stone at the Florentine restoration institute Palazzo Spinelli. Catherine Burnett, International Projects and Cooperation specialist at the institute, provided translation for the interview and additional insight.

“So, in Florence, we’re talking mainly about what’s called Pietra forte, which is the yellowish stone that you often see on the buildings around here, like Palazzo Strozzi,” Costagliola said as an example of a local application for the subject she teaches. Palazzo Strozzi was originally constructed for Filippo Strozzi the Elder, a rival of the Medici family dynasty that ruled over Florence for three centuries and patronized many definitive Renaissance artists including Botticelli, Leonardo da Vinci, and Michelangelo. Other common types of stone in Florence include Pietra Serena, a more bluish one, and the green marble known as Serpentine.

Originally from Napoli, Costagliola chose to be a stone restoration professional because it appealed to her engineering background and allowed her to spend more time outside. The principle of resonance also applies to her professional skillset: a restorer is neither a scientist nor an artist, existing somewhere between these seemingly incongruous disciplines. Sometimes, restorers even face conflict within the boundaries of the science world itself.

“The professions of chemists, of physicists – and biologists more than anything – and restorers sometimes come to blows. They don’t always see eye to eye because the restorer is there to conserve and apply products and processes whereas usually biologists and chemists are there to take surveys and samples but not to act,” Costagliola said.

Ultimately, the final authority on all art restoration decisions is the Soprintendenza Archeologia, Belle Arti e Paesaggio (Superintendency of Archaeology, Fine Arts and Landscape) at the Ministry of Culture. After consulting with the client on a restoration project, whether they be private, a museum, a church, or an antiques dealer, the Soprintendenza must sign off on the restoration plan for any listed work.

However, despite the existence of a conclusive authority, the rules around art restoration are not clear-cut and often change based on regionality. For example, chromatic selection, a technique in which fine lines of pure pigment are placed next to each other to create the optical illusion of the color the artist wanted to achieve, follow a different pattern in Florence and Rome. In Florence, they follow the line of the artist, while in Rome they tend to be applied straight down, called Rigatino Romano.

To try to mitigate the repercussions of the ever-changing politics around art restoration, Costagliola said a key principle employed currently in the field is that of reversibility, or the idea that any process applied to a work of art should be able to be undone as easily as the illusion of a veil carved in marble by a classic Italian master.

“That’s the modern theory of restoration, which has only been developed in the last 30, maximum 40 years,” she said. In the 1960s and ’70s, reversibility wasn’t such a developed concept, leading to the application of products such as Paraloid. Via its own aging process and a chemical reaction known as polymerization, it embeds itself into the stone it was applied to in a way that’s not easily removable. Like the Roman walls that have long since given way to the expansion of Florence but leave grooves in the pavement, it alters the stone on a structural and not just cosmetic level.

The chemical cabinet is a key feature of the painting labs at Palazzo Spinelli, housing solvents that students carefully dab onto non-essential areas of paintings to see if they remove unwanted layers such as dirt or discoloration without damaging original materials. The systematic version of this approach is called the Wolbers test, named after its originator Richard Wolbers, an American art conservator and scientist at the University of Delaware. A second test, the Feigl test, after Austrian-Brazilian chemist Fritz Feigl, helps identify the composition of paints to guide treatment decisions.

The flexibility and resourcefulness of art restoration professionals in being able to borrow from other fields leads to some unexpected sources of inspiration, such as utilizing ingredients frequently found in the cosmetics industry. One example is kaolin, a type of soft white clay. In makeup, its properties as a superfine powder help with mattifying properties, while the same absorbency makes it handy in drawing out impurities on the surface of artworks.

When I first arrived in Italy, I felt that the combination of a rigorous chemistry course and the beauty around me was a dramatic and unusual contrast. However, as time went on, I recognized the way the hidden poetry of organic chemistry reflected in the things I most admire about Florence. The inherent three-dimensional geometry of the subject and the layering of processes to achieve a desired product is akin to the ingenuity that Renaissance artists apply in breathing life into paintings, statues, and architecture. Here’s to hoping the union of art and science lives on through the art restoration profession.