Let’s talk about Ru kiln’s nailing technology, which many people mistakenly think is a flaw.

"Blue as the sky, face as jade, cicada wing pattern, few stars, sesame sticks and nail glaze are enough" are the most basic characteristics for the identification of Ru kiln wares.

In daily communication with customers, we often encounter the question "Why are there three gaps under the cup?"

This is actually a typical misunderstanding of support nails. Many people do not Learn about Ru kiln’s nailing technology.

This kind of tiny sesame nails only appear in Ru kiln wares. Other porcelain kilns cannot imitate them at all, and even the imperial kilns of the Ming and Qing Dynasties cannot imitate them. The best imitations of Qianlong official imitation Ru glazed porcelain also require Support nails and add padding cake. What is strange is that the kiln workers of the Laohudong official kiln in the Southern Song Dynasty (some of whom were workers of the Ru kiln in the north) built when Emperor Gaozong went south to Lin'an to establish his capital, could not replicate the sesame nail. It seems that the kiln workers of the Qingliang Temple Ru kiln The secrets were lost in the long river of history with the invasion of the Jin soldiers, and these excellent Ru kiln craftsmanship were also lost.

With the scientific archaeological excavation, the true identity of the Ru kiln support nails was finally revealed. Sesame nails are actually very common. They are made by kiln workers from local clay. There is no secret at all. In the early days, there were two kinds of pins for making cakes: pins and no pins. The pins were thicker and easier to nail into the cake. It falls off, and the later production is too fine, with thin nail tips; later we produce washers, with or without nails, three or five nails, and six nails for narcissus basins. After the clay is made, Baked into shape, ready to use, it's that simple. The official kiln of the Later Southern Song Dynasty could not make it, and the Jingdezhen kiln could not make it. The reason is probably that the composition of the clay is different (I do not have the composition analysis data of Qingliangsi clay).

The tips of all support nails are hand-kneaded. The top of the tip has a certain arc and only has a small contact surface with the porcelain.

After firing, it becomes sesame. Support nail (a small line mark will be left after the support nail tool is knocked off).

Shanghai Museum Zhou Lili, one of the authors of "The Discovery of Ru Kiln", said in "Appreciation and Collection of Famous Chinese Porcelain" that "there are three sesame-shaped nail marks on the sole of the foot, two of which are close to the foot wall, supporting the The broken cross section is white, and the sesame-shaped nail marks close to the foot wall have become a major feature of Ru kiln wares." There are many supporting nails like this on the bottom porcelain pieces unearthed from the kiln site. In fact, the supporting nails were placed at the bottom of the vessel casually by the kiln workers. The white color of the cross-section of the support nail is due to the color of the bisque-fired porcelain exposed under the cross-section (see the bisque-fired piece).

The shapes of Ru kiln's supporting nails are rich and colorful, with more shapes than other porcelain kilns. It inherited the excellent craftsmanship of Yaozhou kiln in the Tang and early Song Dynasties and creatively developed its own characteristics of supporting firing. "New Discovery of the Ru Kiln Site of Baofeng Qingliang Temple" says: "The large number of saggers, cake mats, washers and other kiln furniture unearthed are also different from those of folk kilns."

In addition to the support nails, a large number of test firing inserts (fire photos) and test firing inserts used to test the kiln temperature were also unearthed from the site. This shows that the temperature at which the azure glaze is fired is strictly controlled.