Guan Kilns
Guan kilns refer to official kilns directly run by the government, and the products of which were exclusively supplied for the imperial courts or governmental officials. Guan kilns started in the Song Dynasty (960-1279), and can be further categorized into Northern Song Dynasty (960-1127) Guan kilns and Southern Song Dynasty (1127-1279) Guan kilns, respectively in Bianjing (present-day Kaifeng of Central China's Henan Province) and Hangzhou of East China's Zhejiang Province.
The earliest record of the Northern Song government's establishing porcelain kilns in Kaifeng appeared as follows in Random Notes While Basking in the Sun by Gu Wenjian of the Song Dynasty: "In the Reigns of Zhenghe and Xuanhe (1111-1125), potteries were set up in the capital to manufacture porcelains. They were called Guan (government) kilns." Their outputs were exclusively for court use.
The actual kiln site has not been discovered, due perhaps to geographical changes in the vicinity of Kaifeng where throughout time, the sediment deposited by the overflowing and shifting Yellow River had buried the civilizations of the Tang (618-907), Song and following dynasties several meters underground. However, quite a number of vessels of Guan ware were preserved by the imperial courts of different dynasties. Emperor Qianlong of the Qing Dynasty (1644-1911), who prized Guan ware, wrote poems in its praise and had the bottoms of Guan porcelain vessels inscribed.
The porcelain of Guan ware used china clay with a fairly high iron content, the paste showing the color of iron black. The rather thick glaze applied gave it the lustrous, bright finish of fine greenish white jade. Its color was paler than the celadon from the Ru Kiln. As the glaze was fired at high temperature, it melted and streamed down the vessels, leaving the glaze on the mouth-rims thinner, hence showing the paste color.
Also, the mouth-rims were separated by a vitreous glaze, giving the color a purplish tinge. The foot-rim was unglazed with the iron-colored paste fully exposed, showing its special feature of "purple mouth-rim and iron foot" -- important in identifying Guan porcelain. Another characteristic of the ware is crisscross, fairly large crackles (decoration patterns of very small surface cracks) like overlapping ice cracks.
After the collapse of the Northern Song Dynasty, Emperor Gaozong of the Southern Song Dynasty moved his capital to Linan (present-day Hangzhou) where the royal family continued its life of luxury.
Carrying on the system of the former capital, the rulers established two government potteries in Hangzhou, which people called the Guan kilns of Southern Song. One was located at Xiuneisi (an office for the maintenance of imperial buildings, including imperial kilns), its product called the Guan ware of Xiuneisi. The other kiln site (discovered at the foot of Tortoise Hill in Hangzhou) was at Jiaotan, on the capital's outskirts.
Random Notes While Basking in the Sun describes the Guan ware of Southern Song as follows: "Potters wash the clay and make molds out of it. The glaze color is lustrous and transparent. The vessels are treasured by people all over the country."
The porcelain vessels of Guan ware of the Southern Song Dynasty have often been discovered in the tombs of nobles and high-ranking officials in Nanjing (East China's Jiangsu Province) and elsewhere. Although their quality is inferior to those of the Northern Song's Guan ware, they are still excellent celadon specimens.
The exact kiln site of the Xiuneisi Guan ware having yet to be found, there have been differing views about Xiuneisi Guan kilns among Chinese academic circles. Some believe there were no such kilns at all because Xiuneisi was a government yamen (office) and as such it could not possibly have allowed kilns built within its confines. Others believe Xiuneisi Guan kilns were located in Longquan because Xiuneisi ran some of the workshops in Longquan kilns. The question remains unsolved, as neither argument is convincing enough.