We resume our discoveries in Dr Tang Hui’s doctoral thesis on 18th century Chinese porcelains published in 2017 where he cover some basics of the genre, which might be off putting to advanced collectors, but which we find worthwhile.
He notes the distinction between overglaze and underglaze decoration, the latter being the application of enamel to the unfired body which typically requires only one firing, whereas the former applies enamel to the glazed already-fired body which then necessitates a second firing. We can already see that the overglaze productions are more labor and resource intensive.
The prime example of underglaze decoration is the blue and white wares for which China is so famous. One of the advantages of the overglaze decoration is the availability of are more colors since fewer enamels can withstand the high temperatures used for underglaze decoration.
Although known as early as the 13th C., overglaze enameled wares were not produced in abundance until about the mid 16th C. At this point in his narrative Hui notes the prodigious inflow of silver due to porcelain trade, a point we anticipated in part 1.
Due to the destruction of kilns during the late Ming and transitional periods, Europeans, especially Dutch, turned to Japan for porcelain, a turn which prompted competition and innovations in Chinese porcelain production, most notably in material and form. An example of Chinese copying was what we know as Imari wares. It is thus interesting to note that Chinese porcelains were influenced by both Asian – ie Japanese influences, as well as European novelties.
Of further note, Hui states that famille verte was introduced in the late 17th C but manufacturing techniques were very similar to those of the 15th C. However, famille verte is accompanied by overglaze blue made from crushed glass (yet we do not have famille bleu). The period around 1700 is also the time at which fired-on gilding appears. It also witnesses the use of talc over kaolin in porcelain which creates a softer but whiter and lighter body.
Hui states that enameled wares, particularly on copper and glass, appeared in the court during the 1680s, which quickly led to experimentation to apply such enamels to porcelain under direct imperial control.
At this point Hui embarks on the discussion of porcelain manufacture, motivated in part by the technical complexity of creating and applying polychrome enamels to porcelains. He describe a series of very specialized steps which shows the scope and sophistication of porcelain production. It was not a studio artist affair where one person handled all of the production – like a full stack software developer - but rather a chain of specialized steps which yielded the final output, the details of which the reader is invited to read for extra credit.
Before drawing to a close this installment, Hui implies, though I have not found it stated explicitly, that the skills required for polychrome enameling were an order or more higher that needed for underglaze ceramics. This consideration may influence buying decisions.
Actually, one more point is in order before closing. Italian Giuseppe Castiglione (1688-1766) published in Chinese with assistance from Nian Xiyao, a one-time supervisor of the royal kilns at Jingdezhen, Visual Perspectives, a work on dimensional depictions which would have significant impacts on Chinese porcelains. Thus it was not merely with enamels that Western influence helped shape Chinese porcelain.
We will pick up again soon with our 3d installment of Dr Hui’s thesis, starting, no less remarkably, with his chapter 3.