Bo Cai Ru Yao 'Si Fang' Si Leng

DESCRIPTION: Ru Yao is the first of the five famous kilns. Historically, it has been used as articles or collections for the royalty or nobility. Due to various invasions from outsiders during the Song Dynasty, the primary recipe of the Ru Yao became forever lost, thus halting all Ru Yao production until 1952. In 1952, Premier Zhou Enlai instructed "to develop Chinese cultural heritage and restore Ru Yao production". After hundreds of experiments and studies, the first batch of bean-green glaze crafts were fired in 1958. In August 1983, the Ru Yao sky-blue glaze was appraised by experts, and had finally reached and surpassed the level of quality of Ru Yao during the Song Dynasty. Today, the first Chinese company to complete the continuation of Ru Yao's top technology is Bo Cai Ru Yao.

MATERIAL: Bo Cai Ru Yao is extremely complex. The porcelain glaze is made of more than 10 kinds of minerals, crushed, filtered three times by 80 meshes and 120 meshes, and then dredged with magnets, and then grouted into molds. After drying, the ceramic body should be polished over three times so as to make the surface suitably smooth. The burning process is then carried out for 10 hours, with temperatures reaching over 800°C, only then to be ground twice after the burning process. The glaze is then applied to air-dried burnt porcelain for another 13 hours. There are a total of 18 detailed processes in making Ru Yao porcelain. In fact, its firing process is an oxidation-reduction process, which takes away oxygen atoms from the silicate at 1260°C.

DIFFICULTY: Due to the complexity of the production process, the overall yield per kiln is only 17%.