Carving Out Earth and Filling It Back In: How Goryeo Potters Perfected Sanggam Celadon

Sixty-nine cranes soar across a blue sky. The cranes inside the double rings rise toward the heavens, while those outside the rings descend toward the earth. This is the surface of the National Treasure “Celadon Maebyeong (Prunus Vase) with Inlaid Cloud and Crane Design,” held by the Kansong Art Museum. Yet these cranes and clouds are not painted with a brush. They are patterns the potter made by carving out the surface of the vessel with a carving knife and filling the grooves with clay of a different color. Carving away clay only to fill the hollows back in with other clay looks, at first glance, like an exceedingly laborious method. Let us follow how it became the decoration that represents Goryeo celadon.

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“They Call It Bisaek” — The Blue That Impressed a Song Envoy

Goryeo celadon began under the influence of the Yue kilns (越州窯) of southern China. It was not a clear blue-green from the start. Some early celadons have a brownish tone, such as the “Celadon Jar Inscribed with the Fourth Year of Chunhua,” made in 993. The kilns changed as well. In early Goryeo, potters in the Gyeonggi and Hwanghae regions used brick kilns that adopted Chinese technology, while potters in the Jeolla region used clay kilns that carried on the tradition of earthenware kilns. By the middle Goryeo period, the brick kilns had disappeared, and celadon came to be fired in clay kilns.

The blue color comes from the skill of handling clay, glaze, and fire. A vessel is first given a bisque firing, then coated with glaze and fired again; during this second firing the mouth of the kiln is closed off to cut down the oxygen getting in, and this is what brings out the jade-green color. The fame of this color crossed borders. Xu Jing (徐兢), an envoy of the Song dynasty who came to Goryeo in 1123, wrote in his Gaoli Tujing (高麗圖經, Illustrated Account of Goryeo): “The people of Goryeo call the blue color of their pottery bisaek (翡色). In recent years the craftsmanship has become refined, and the color has become even finer.” An official from China, the homeland of celadon, took the trouble to record the color of Goryeo celadon.

How to Paint with Clay — Sanggam (象嵌)

The bisaek color alone was beautiful enough, but Goryeo potters found a way to add patterns on top of it. Sanggam was originally a term from metalcraft. It referred to the technique of carving out a surface and setting another material, such as gold or silver, into it to create a pattern, for example eunipsa (銀入絲), in which silver wire is inlaid into bronze. In ceramics, too, decoration made by carving the surface and filling it with clay of a color different from the body is called by the same name, and celadon decorated this way is called sanggam celadon.

The technique of carving out clay and filling it with other clay did not originate in Goryeo. According to A Cultural History of Korea (Hanguk Munhwasa), published by the National Institute of Korean History, the technique is known to have begun at the Huangbao kiln (黃堡窯) in Shaanxi Province, China, and was also tried at northern Chinese kilns such as the Yaozhou and Cizhou kilns, but it was not a common technique. In Goryeo as well, around the 10th century when celadon production began, line inlay was used sparingly on special vessels such as the janggu (hourglass drum). What Goryeo potters did was raise this rare technique to the center of celadon decoration. Sources differ on where to place its beginning. A Cultural History of Korea traces it back to the small-scale attempts of around the 10th century, yet explains that inlay became established as the decoration of high-quality celadon in the late 12th century. The Encyclopedia of Korean Culture dates the first use of inlaid patterns on celadon to the first half of the 12th century, and the great increase in refined inlaid celadon to the mid-12th century. Either way, inlaid celadon came into full bloom from the mid-12th century onward. The “Celadon Bowl with Inlaid Posanghwa and Scroll Design,” said to have come from the tomb of the scholar-official Mun Gong-yu (文公裕), who died in 1159, is counted as evidence of the level of inlay around that time. There are, however, differing views on the reliability of the excavation record and on the date of manufacture.

In Goryeo of the same period, other crafts also flourished: ipsa, inlaying gold and silver into metal; pyeongtal, attaching thin sheets of gold and silver to wooden vessels; and najeon chilgi, lacquerware inlaid with mother-of-pearl. A Cultural History of Korea explains that these crafts show traces of influencing one another in their forms. Each craft is made in its own way, but metal ipsa in particular, in carving out the body and setting another material into it, is regarded as the same technique as celadon inlay under a different name. The Gwangju National Museum describes celadon inlay as “a creative technique that can be called epoch-making in the history of East Asian ceramics.”

Carve, Fill, Scrape, and Fire Twice

The process demands patience. Let us follow the explanation in the Encyclopedia of Korean Culture. First, the vessel is shaped, and when it is half-dry, a pattern is incised into the surface with a carving knife. White clay (baekto) or red clay (jato) is brushed into the carved grooves. When the clay has dried, the excess clay on the surface is scraped away. The clay then remains only in the incised areas, and the pattern appears. The vessel is dried completely and given a bisque firing, then coated with celadon glaze and fired a second time to finish.

White Clay Turns White, Red Clay Turns Black

Here lies the subtle charm of inlaid celadon. After passing through the intense heat of the kiln, baekto turns white and the red jato turns black. That pattern then glows softly through the transparent celadon glaze. Because the potters knew precisely this property, by which the components in the clay change color when they meet fire, they could calculate in advance and carve a black-and-white picture that was invisible before firing. The black-and-white double rings and the white cranes and clouds of the Kansong Art Museum’s maebyeong were all filled in this way with the two kinds of clay.

The cloud-and-crane design is not unique to the Kansong Art Museum’s maebyeong. The Encyclopedia of Korean Culture lists cloud-and-crane, wild chrysanthemum, willow and waterfowl, and peony among the inlaid patterns found at the Gangjin kiln sites. Across the ocean, the Metropolitan Museum of Art in the United States also holds a cloud-and-crane maebyeong made in the late 13th century. Thin black lines surround its white cranes and clouds, showing well the skill of using two kinds of clay together within a single pattern.

Gangjin and Buan, the Kilns That Fired Inlaid Celadon

This intricate work did not happen just anywhere. A Cultural History of Korea explains that inlaid celadon was concentrated in centers of high-quality celadon such as Gangjin and Buan and is rarely found at provincial kilns. From this, the book concludes that inlay was a high-end technique used for vessels made for the upper class.

The kiln sites around Daegu-myeon, Gangjin-gun, South Jeolla Province, were designated a Historic Site in 1963. According to the Encyclopedia of Korean Culture, 65 kiln sites remain in Yongun-ri, most of them early kilns of the 10th to 11th centuries. Sadang-ri has 45, most of which date from the first half of the 12th century to the 13th century; the area around Dangjeon village in particular was where kilns clustered throughout the 12th century, and it shows outstanding bisaek and inlay techniques. The course by which celadon began and matured remains, as it were, in the kiln sites along the valley.

The area that rivaled Gangjin was Yucheon-ri, Boan-myeon, Buan-gun, North Jeolla Province. A Cultural History of Korea explains that in the first half of the 13th century more inlaid celadon was made in Buan than in Gangjin. Why Buan suddenly came to the fore has not yet been determined; there is only the conjecture that it may have been related to the changed power structure after the military coup of 1170. A Cultural History of Korea also surmises that the Kansong Art Museum’s cloud-and-crane maebyeong was made in Buan around the 13th century, but the National Heritage Portal gives its date of manufacture as the late 12th century, so views on its date differ.

The Maebyeong That Kansong Saved

There is a story behind why this maebyeong remains in Seoul today. According to History Net of the National Institute of Korean History, the maebyeong is said to have originally lain in a tomb on Ganghwa Island, from which a tomb robber secretly took it out and sold it. During the Japanese colonial period, Kansong Jeon Hyeong-pil bought the maebyeong from a Japanese man named Maeda, and he turned down another Japanese man’s offer to pay twice the price. After liberation, the maebyeong was designated a National Treasure on December 20, 1962. For a long time it was called “National Treasure No. 68,” but following criticism that designation numbers were misread as a ranking of value, designation numbers were dropped from heritage names from November 19, 2021, and it is now called “National Treasure Celadon Maebyeong with Inlaid Cloud and Crane Design.”

Decline, and the Line That Led to Buncheong Ware

Every golden age comes to an end. In late Goryeo, as the Mongol invasions and the interference of the Yuan dynasty continued, celadon entered a period of decline. Celadon from this time tends to show a yellowish-green surface that has lost its bisaek, along with inlaid patterns that grow cluttered and coarse and repeat the same motif. By the end of Goryeo, the kilns firing celadon had dwindled to a few places, such as Sadang-ri in Gangjin and Yucheon-ri in Buan.

Yet the technique was not cut off. The Goryeo Celadon Museum explains that at kiln sites such as Suyu-dong in Seoul and Hwangji-ri in Yecheon, one can trace how the inlaid celadon of the very end of Goryeo carried over into the buncheong ware of early Joseon. Buncheong ware is pottery shaped from the clay used to make celadon, coated with white clay, and then fired; the name is short for bunjang hoecheong sagi (gray-green stoneware decorated with white slip). Buncheong ware continued to use inlay, in which patterns are carved and filled with clay, and added further techniques such as stamping (印花), in which the same pattern is pressed repeatedly with a stamp and then filled with white clay, and incising, in which patterns are scratched in with lines. This also coincided with the wishes of a new ruling class centered on Confucianism, who preferred frugal and practical vessels to ornate ones. Buncheong ware was made for about 200 years, from the late 14th century at the end of Goryeo to the mid-16th century in Joseon.

What We See Today

When we stand before a single maebyeong and count its sixty-nine cranes, what we face is not merely an old vessel. It is the time of potters who did not stop at the technique they had received from others, who understood how two kinds of clay turn white and black when they meet fire, and who painted with that very property. Thanks to people who kept asking, to the end, what could be made from the same clay, cranes rise from every place that was carved out and filled back in.

References

• Sanggam (Inlay) — Encyclopedia of Korean Culture (in Korean)
• Celadon Maebyeong with Inlaid Cloud and Crane Design — Encyclopedia of Korean Culture (in Korean)
• Goryeo Celadon Kiln Sites in Gangjin — Encyclopedia of Korean Culture (in Korean)
• Buncheong Flask with Incised Lotus Design — Encyclopedia of Korean Culture (in Korean)
• The Making of Inlaid Celadon — A Cultural History of Korea, History Net (National Institute of Korean History) (in Korean)
• Goryeo Celadon, the Ceramics Used by the People of Goryeo — History Net (National Institute of Korean History) (in Korean)
• The Ceramics of Joseon: Buncheong Ware and White Porcelain — History Net (National Institute of Korean History) (in Korean)
• The History of Goryeo Celadon — Goryeo Celadon Museum (in Korean)
• What Is Goryeo Celadon? — Gwangju National Museum (in Korean)
• National Treasure Celadon Maebyeong with Inlaid Cloud and Crane Design — National Heritage Portal, Korea Heritage Service (in Korean)
• National Treasure Celadon Melon-shaped Bottle — National Heritage Portal, Korea Heritage Service (in Korean)
• Goryeo Celadon — Wikipedia (in Korean)
• “National Treasure No. 1” Sungnyemun? “National Treasure” Sungnyemun! … Cultural Heritage Designation Numbers Abolished — Newsis (November 19, 2021) (in Korean)

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