CHAPTER X
CRYSTALLINE GLAZES
Flambé or transmutation glazes of the Chinese potters—The Royal Copenhagen Factory produces the first specimen of crystallized glaze in 1886—Blue crackled glaze produced with design under control.
During the last decade of the nineteenth century the Western potter came under the spell of the modern chemist. Scientific study applied to the body and glaze and vitrifaction of the materials composing porcelain and faience, together with a closer study of the exact conditions of temperatures in the kilns, resulted in the discovery of certain well-defined decorative qualities in connection with glazes which, after considerable experiment, offered practically a new field for colour-work of a very beautiful nature.
In the flambé or transmutation glazes for which the Chinese potters were renowned, the effects of variegated or splashed colour are due to the capricious action of the fire on the glazes during the firing process. The single-coloured glazes of the Chinese applied to vases and other objects have been much prized by Europeans. The tints are very numerous, sea-green or celadon, yellow, red, blue, purple, brown, black, and other tones. These include the celebrated sang-de-bœuf colour of French collectors, so highly prized in China. It is thought probable that many of these single-colour glazes have been applied at a somewhat lower temperature, termed by the French demi-grand feu.
The mottled classes owe their appearance less to the difference in the colouring matter than to the manner in which it is applied. They are termed in French flambé, and there is no doubt that they were originally accidentally produced. According to the letters of a Jesuit missionary, Père d'Entrecolles, written in the early years of the eighteenth century, such vases were called Yao pien or transmutation vases. Such types, with turquoise colour passing into green, green melting into purple, and amber fading into grey, are suggestive of the permutation of colour harmonies which these transmutation glazes undergo in the furnace.
Beside the flambé glazes there are crackled glazes of turquoise-blue, apple-green, or of greyish white. This crackle porcelain is now artificially produced, but it doubtless owes its origin to accident and caprice of firing.
