CHINA
POUVCHROMATIC GLAZES
CRACKLE.
One of the most remarkable methods of decora- tion employed in China was that of crackle. Ware of this type was called Sz-4. Its invention is ascribed to the potters of the province of Shen-si and to the early years of the twelfth century. The strong probability is that the so-called invention was in reality accidental. It is easy to conceive that where glazing material and péte which differed sensibly in composition were exposed to the same degree of temperature in the kiln, the unequal expansion of the two broke the continuity of the glaze. Unable to conquer this tendency, the shrewd Chinaman conceived the idea of utilising it, and ultimately elaborated the conception to a high degree. Two methods of producing crackle are de- scribed in the Tao-/u. The first was to alter the com- position of the glazing material by adding a certain quantity of steatite to it; the second, to sun-dry the glaze piece and then plunge it into cold water before stoving. A brown, red, or blue colour was imparted to the crackle by rubbing the surface of the vase, while still hot — that is to say, before the contraction of cooling had caused the edges of the crackle to close — with Indian ink, red ochre, or cobalt. An- other practice, pursued in later times, was to re-heat the vase slightly and then dip it in a solution of colour- ing matter. By either method, but especially by the latter, not alone the crackle but also a portion of the adjoining surface of the glaze received a carmine tint. It is recorded of the brothers Chang, celebrated manu- facturers of Lung-chuan céladon during the Sung dy- nasty, that the ware of the elder — distinguished as Ko-yao — was crackled, whereas that of the younger
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