Porcelain Defined: From a Cowrie Shell to a Soft-Paste Teapot
“These dishes are made of a crumbly earth or clay which is dug as though from a mine and stacked in huge mounds and then left for thirty or forty years exposed to wind, rain, and sun. By this time the earth is so refined that dishes made of it are of an azure tint with a very brilliant sheen” (Marco Polo, cited in De Waal 2015, 7).
The word “porcelain” derives from the Italian word for a type of seashell, porcellana (cowrie shell), and comes down to us across the centuries via Marco Polo, who encountered Chinese ceramics during his travels in Asia. While in captivity in Genoa, ca. 1299, he dictated his famous travel reports to his cellmate, including a discussion of Chinese ceramics, which compared their “brilliant white surface” to the “marine snail porcella” (Meister and Reber 1980, 7; Raffo 1982, 79).
The secret for making true Chinese porcelain long eluded the Europeans, who were only first able to create this Chinese-style porcelain in 1709 at the German Meissen factory. This “true” porcelain was known as “hard paste”; the hard-paste method did not emerge in France until decades later.
Soft-Paste vs. Hard-Paste Porcelain
The famous wares of the Vincennes and Sèvres Porcelain Manufactories were thus, in the early years, exclusively “artificial” porcelain, known as soft-paste (pâte tendre), starting with the founding of the Vincennes factory in 1745, and continuing through its move to Sèvres in 1756, until the factory was able to produce hard-paste porcelain in the 1770s. Even at that point, the Sèvres factory continued to produce soft-paste pieces for a while. Most of the objects from the Fritzsche Collection are soft-paste porcelain.
Although originally developed by Westerners in the seventeenth century in a quest to imitate Chinese porcelain, soft paste soon developed a life and legend of its own. In fact, in an irony of history, while it was meant to be a substitute for “authentic” Chinese porcelain, many connoisseurs and scholars believe it is more beautiful than hard-paste porcelain. Svend Eriksen proclaims that the “ivory-white tone” of soft-paste porcelain “is quite simply more beautiful … than the glittering white surface of hard-paste porcelain” (Eriksen and De Bellaigue 1987, 42), while Dr. Fritzsche agrees, noting that “the colors seem to melt more into the soft paste” (Fritzsche 2019).
A particular feature of soft-paste was this fusion of colors into the glaze, which is lacking in hard-paste: “The lead-glaze of soft-paste porcelain … unite[s] with the colors in such a way that the painted decoration achieves a unique depth and brilliance” (Eriksen and De Bellaigue 1987, 42; see also Dawson 1994, xv; Arend 1998, 39). One reason for this is that, on hard-paste porcelain, “the colors do not sink into the glaze, but tend to sit on top in very slight relief” (Roth and Le Corbeiller 2000, 381).
Ingredients, Glaze, Firing, Color
Hard-paste porcelain (pâte dure), first produced in Western Europe in 1709 at the German Meissen factory, was composed of kaolin (a pure white clay; the term means “high peak”) and petuntse (a type of feldspar rock; the term means “little white bricks”), and was fired at very high temperatures (Gray 1982, 12). Soft-paste porcelain (pâte tendre), by contrast, was fired at lower temperatures, and was created from a mixture referred to as a frit, consisting of white clay mixed with diverse ingredients such as sand and ground glass (Roth and Le Corbeiller 2000, 381; Arend 1998, 19; Dawson 1994, xiv).
Unlike hard-paste, soft-paste porcelain required four kiln firings (fournées). After an initial “biscuit firing” (unglazed), the pieces were coated with a thick, shiny lead glaze (couverte), and then fired a second time (the “glaze firing,” also known as the “glost firing”). Most ground colors were applied after the glaze firing, with the exception of certain blue ground colors made with cobalt, such as lapis-lazuli blue (bleu lapis). Painted decoration, known as “enamel decoration” or “enamel colors” (émail), and often translucent, was added after the glaze firing, followed by the “enamel firing” (fournée de peinture). Finally, gilding was applied, followed by an additional firing.
In the earliest years, Vincennes porcelain had a white, uncolored ground, covered with the clear lead glaze that was applied after the biscuit firing. An example of this early white ground with colorfully painted “enamel” decoration is the Snake-Handled Bowl (ca. 1750, slides 7a–b), in the Seattle Art Museum collection (SAM, no. 95.53). Thereafter, special ground colors (fonds) were introduced. Read here about the development of blue ground colors at Vincennes.
References: Dawson 1994, xiv–xv; Eriksen and De Bellaigue 1987, 40–42, 56–59; Arend 1998, 19, 41; Savill 1988, 3:1172–74; Meister and Reber 1980, 7; Tait 1972, 8–25; Roth and Le Corbeiller 2000, 381; Fritzsche 2019; Gray 1982; Raffo 1982.