Page 334 - Chinese pottery and porcelain : an account of the potter's art in China from primitive times to the present day

198 Chinese Pottery and Porcelain

to mix a certain ingredient with the glaze which produced a crackle
when fired. There are constant references to this ingredient under
the name of sui yu (crackle glaze) in the letters of Pere d'Entrecolles

—in connection with various monochromes, and in the first letter,^

the following definite account appears : " It is to be observed
that when no other glaze but that composed of white pebbles ^ is
added to the porcelain, the ware turns out to be of a special kind

=known as tsoui ki {sui ch'i crackled ware). It is marbled all

over and split up in every direction into a infinite number of veins.
At a distance it might be taken for broken porcelain, all the frag-
ments of which have remained in place. It is like mosaic work.
The colour produced by this glaze is a slightly ashen white."

The effect of this ingredient of the glaze whatever its composition

may have been is easily understood. All porcelain and pottery

—undergoes a considerable amount of contraction from loss of
—moisture, etc. in the kiln, and to obtain a perfectly even glaze

it is necessary that the contraction of the glaze should be the same

as that of the body. Clearly this ingredient caused the glaze to
contract to a greater extent than the body, and so to split up into
minute fissures. The Chinese were able to control to a great
extent the size and nature of the crackle, as is shown by the appearance
of alternate bands of large and small crackle on the same piece.

The methods of colouring the crackle include rubbing red ochre,
ink, and decoction of tea leaves into the cracks before the ware
was quite cool. Another method is described by Bushell (0. C. A.y
p. 511) by which a white crackled ware was stained pink or crimson.
The vessel was held in the fire in an iron cage until thoroughly heated,
and then water mixed with gold-pink colouring matter was blown
on to it. This, however, is a later process. Most of the mono-
chrome glazes are occasionally crackled, but the most characteristic
colours of the crackle glazes are the greyish white (the blanc un peu
cendri of P^re d'Entrecolles), and light buff, which were probably

^ See Bushell, Tao shuo, loc. cit., p. 195.
" The Tao lu (see Julien, p. 214) informs us that the sui ch'i yu (crackle ware glaze)
was made from briquettes formed of the natural rock of San-pao-p' dng. If highly

refined this material produced small crackle ; if less carefully refined, coarse crackle.
In reference to sui ch'i in an earlier part of the same work, we are told that the Sung

potters mixed hua shih with the glaze to produce crackle. Hua shih is a material of

the nature of steatite, and Bushell (0. C. A., p. 447) states that the Chinese potters
mix powdered steatite with the glaze to make it crackle. It is, then, highly probable
that the "white pebbles" of P6re d'Entrecolles and the rock of San-pao-p'eng are the
same material and of a steatitic nature.