What are the green materials used in blue and white porcelain?
One of the most famous is "Su Ma" or "Su Mu Ma Qing," which is known for its deep, rich blue with a greenish tinge. The name is believed to come from the Persian word "Sulayman," possibly referring to a person who discovered the cobalt ore in the Kumsa village of the Bosca Mountains. Another theory suggests that "Su Ma" is a transliteration of the English term "smalt," meaning dark blue pigment. This material is high in iron and low in manganese, producing a thick, vivid blue with a characteristic "rust stain," often called "tin light." It was widely used during the Yuan, Ming, and early Qing dynasties, especially in the imperial kilns of ancient Persia and present-day Syria.
"Equality Qing," also known as "Tang Tangqing," comes from Leping, Jiangxi. It was popular during the late "blank period" and the early reigns of Chenghua, Hongzhi, and Zhengde. This material produces a soft, stable blue, contributing greatly to the fame of Chenghua blue and white porcelain.
"Shiziqing," or "Shiqing," is sourced from Gao'an, Yifeng, and Shanggao in Jiangxi. When used alone, it can produce a dark or even black tone, but it was commonly mixed with other materials in Ming and Qing porcelain. It was often used in official kilns for blending with other colors.
"Back to green" refers to various types of cobalt found in regions like Xinjiang, Yunnan, and the Western Regions. These materials are vibrant and fragrant, but they don’t work well on their own. They were often blended with Shiziqing. During the early Ming Dynasty, especially in the Jiajing and Wanli periods, two types were used: "Xiaoqing" (10% mixed with Shiziqing for filling) and "Zhongqing" (40% mixed for outlining), each offering distinct visual effects.
"Zhejiang material," also called "Zhejiang Qing," comes from Shaoxing and Jinhua in Zhejiang Province. Known for its superior quality, this material produces a bright green-blue hue. It was widely used in the Jinghua Town imperial kilns during the middle of the Wanli period and into the Qing Dynasty.
"Zhuming material" originates from Xuanwei, Huize, and Yiliang in Yunnan. It is considered the best among local cobalt sources, known for its bright and pure color. Kangxi-era blue and white porcelain often used this material.
The domestic cobalt materials mentioned above are generally high in manganese, giving them a more natural, earthy tone compared to modern synthetic alternatives.
Lastly, there's "chemical green material," made from chemically processed cobalt oxide. While it produces a vibrant, consistent blue, it lacks the depth and richness of traditional natural pigments. It tends to look artificial and is less valued in fine porcelain. Pieces made with this material often lack the subtle beauty and character of those using authentic cobalt sources.
Dongguan HengTaichang Doors Co, Ltd. , https://www.dghtcdoor.com