Unlocking the mysteries of classical Greek pottery

Drinking vases still gleam after 2,500 years

Few customs better illustrate the culture of Classical Greece than the symposium, a form of drinking party where men of social standing gathered to discuss the great issues of the day.

As courtesans and others entertained them, they spoke and sipped wine from bowl-like vessels known as kylikes, red-and-black ceramic pieces long considered the quintessential form of Athenian pottery.

But the cups also hold secrets of that culture, secrets that scholars such as Sanchita Balachandran are using new methods to unravel.

Balachandran, the curator-conservator of the Johns Hopkins Archaeological Museum in Baltimore and a lecturer in Near-Eastern studies, has spent the past year leading an interdisciplinary research team on a quest to recreate the vessels. The group has combined the efforts of art historians, artists, arts conservators and materials scientists, seeking an answer to a question that has baffled scholars for centuries: How did ancient artisans make these masterpieces?

How, for instance, did they create a thin glaze that would gleam for two millennia? How did they achieve a lightness and balance that modern potters envy? How did they produce shiny black and less-shiny red surfaces side by side?

"We'd love to be able to [recreate] these pieces, but it's extremely complex," said Balachandran, who made several specimens from the university's antiquities collection available for the study. "We're still just learning to ask the right questions."

About 10 inches across, 4 inches tall and dating to between the sixth and fourth centuries BCE, each features the delicately rendered image of a subject of the day: a citizen, a scene, a favorite god.

In studying the vessels, art historians long led the way, but their attention was limited chiefly to the images they bear. Scientists joined the fray in the 20th century, using materials analysis techniques such as X-ray diffraction and electron microscopy to explore what the vessels are made of.

During the past decade, researchers at the Getty Conservation Institute in Los Angeles even used a cyclic particle accelerator as part of a five-year study, the Athenian Pottery Project, that analyzed fragments down to the molecular level.

But as much as Balachandran, an arts conservator, appreciated the beauty of the artistry and the brilliance of the scientific researchers, it frustrated her to see how little the research on the vessels bridged the gap between the art and the science.

"It's so clear that the art and the materials were dependent on each other, it only makes sense to explore them together," she said, adding that she hoped to spark "a constructive conversation among people who bridge these worlds."

Armed with a grant from the Andrew W. Mellon Foundation, she enlisted Matt Hyleck, a Baltimore potter, and launched a course, "Recreating Ancient Greek Ceramics." She chose 13 undergraduate students from a variety of majors to take the course.

She later added Patty McGuiggan, a Hopkins materials science professor, to her team and expanded her research thanks to a grant from the university's Discovery Award program for cross-disciplinary studies.

Using available scientific and cultural knowledge as a foundation, the team tried to create their own kylikes, testing existing theories as they worked their way through what scholars believe were the basic stages of producing them.

They learned long ago, for instance, that the images on the pots were not rendered in paint but in slip, a form of liquefied clay that contains iron. Painters created the images on the pots in that medium, and kiln masters achieved the signature red and black by putting each piece through a kiln firing consisting of three carefully managed phases.

In the first phase, the artisans baked the pieces at about 1,650 degrees Fahrenheit with the vents of the kiln open, a process that turned everything red. In the next phase, they maintained a similar temperature but closed the vents and introduced wet organic substances, which turned the pieces black. Finally they reopened the vents, a step that kept only the areas painted with slip a shimmering black and the rest of the vessels red.

Chemists now know they had put the iron in the slip through processes called oxidation, reduction and reoxidation, introducing carbon monoxide in the second phase. (Carbon monoxide turns red hematite into deep black magnetite, to name one known chemical pathway.)

But there are so many variables in the process — the composition of the clay and slip, the brush materials the painters used, the makeup and design of the kilns, the duration and heat of firings — that modern investigators can only feel their way through it, reasoning backward about how the Greek artisans might have proceeded.

The students fashioned their own pieces, helping to create clay and slip from scratch, painting original images and firing the vessels in a replica kiln the instructors built. They put the works through the firing process, experimenting with the variables. Few got the results they were after. Several paintings vanished. A few pieces exploded in the kiln. But some students achieved areas of representative black, and several got results that put conventional wisdom to the test.

The group found, for example, that they could fire the vessels at temperatures previously thought unreachable. Some saw through a microscope that when the Greek painters signed their names, the lines crossed others in a way that suggested two firings.

Certain camps of classicists have long insisted that there could have been only one.

"I didn't know much about this form of pottery before, but I learned from spending time with the literature that the art history and science camps dig in about their theories and aren't so friendly with each other," said Hyleck, an educator and resident artist at Baltimore Clayworks, a ceramics center.

Marc S. Walton, a materials scientist at Northwestern University, said Balachandran's course represents a cutting-edge approach in a developing field.

"It delves deeply into a single topic, much as aspecializedresearcher would do, [and] this allows the student to see the entire process of inquiry — specifically how the physical science can give us new insights into the materials of past cultures.

"Understanding how the ancient Greeks made pots not only tells us about the pots, but more importantly, it gives a unique perspective on the potter," adds Walton, who helped direct the National Science Foundation-funded Getty study.

Balachandran will spend this semester doing more research in hopes of offering the class again, should more funding come through after July when her current Discovery grant ends.

Senior Travis Schmauss, a Johns Hopkins materials science major who took the class, says working with Balachandran taught him more about ancient Greek life than how they partied, debated or made carbon monoxide.

"There's so much science behind them," he says of the kylikes, "but just being in the workshop, working hands-on with the materials they used, you get a sense of how they did it. It was a powerful way to learn."

jonathan.pitts@baltsun.com

For more

To see "Mysteries of the Kylix," an 18-minute film on the project directed by Bernadette Wegenstein of the Johns Hopkins University Center for Advanced Media Studies, visit:

http://archaeologicalmuseum.jhu.edu/the-collection/object-stories/recreating-ancient-greek-ceramics/film-mysteries-of-the-kylix/

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