A deep yet brilliant red, Jihong is one of the classic glaze colors of Jingdezhen. Although the ingredients in the recipe are known, the difficulty of firing this glaze has meant that many porcelain studios choose an easier, more modern recipe to achieve a red glaze. Porcelain pieces that are made with the original glaze recipe for jihong are known as "fanggu" porcelain for their adherence to the original recipe.
The requirements for firing the glaze successfully are quite demanding. Firing a jihong glazed piece with a qinghua blue pattern or painting is even more difficult.
Jihong is an old recipe for red glaze, originating in the early Ming Dynasty. Jihong 霁红 can be translated as "ruby red." The name is sometimes also written 祭红 Jihong "sacrificial red," from the characters 祭祀 meaning "to sacrifice." Jihong glazed porcelain vessels were originally used in imperial sacrificial ceremonies during the Ming Dynasty, before the glaze was adopted for other wares.
Antique Ming Dynasty jihong glazed porcelain cups:
Studios achieve the famous, deep ruby red of Jihong by using copper oxide in the glaze. When fired in a reduction (low oxygen) environment at temperatures between 1280-1285°C the copper oxide will give jihong its classic red color. The firing range is very narrow at only 5 degrees. If the temperature or environment is off by even a little, the glaze will appear light-pink-to-white or dull, dark and brown-grey.
Adding cobalt blue (qinghua) pigment compounds the difficulty because of the different firing requirements for this color. Cobalt blue needs to be fired at around 1300°C for best results. Firing both the jihong glaze (red) and cobalt blue pigment together requires the kiln to fire at a high enough temperature for the cobalt blue, but not so high that the jihong glaze is ruined. Most of the time, the studio fails to achieve this balance. The failure rate for Jihong Qinghua porcelain is around 70%.