Ellen Hsieh, Christian Fischer
Blue-and-white porcelain is a type of ceramic decorated with an underglaze cobalt-based blue pigment and fired in a single step at high-temperature. In archaeological research, it is one of the most distinguishable materials because of its durable patterns. The origin of blue-and-white porcelain can be traced back to the close interaction between East and West Asia during the Yuan Dynasty (1280-1368 AD) when China was part of the Mongolian Empire, and it achieved maturity in Jingdezhen, famously known as the city of porcelain. Until the beginning of the 18th century, the production technology of blue and white porcelain remained a mystery to Europeans as attested by a 17th c. publication reporting that porcelain was made with a material composed of plaster, egg and oyster shell, sea locusts and/or similar creatures, and needed to be buried by the head of the family for eighty years! Today, the general recipe and production process of blue-and-white porcelain are not a secret anymore and the stylistic features and visual specificities of wares from both official (only for court use) and folk (for common use and export) kilns are well established and documented. However, in an archaeological context, especially when examining large amounts of small shards, often without recognizable patterns, the identification of the subtle variations of blue-and-white porcelain and/or the attribution to a particular production area is still a challenging endeavor.
Scientists have achieved ways to distinguish products from several sources by using a variety of advanced laboratory-based instrumentation. While these studies have provided an invaluable insight into site-specific compositional characteristics of the body, glaze and pigment, most of them have nevertheless focused on the well-documented products from official kilns, which have been valued as a symbol of Chinese civilization for the last seven hundred years. On the other hand, blue-and-white porcelain production from folk kilns, which was widely exported alongside the development of global trading networks and had crucial cultural impact in various regions of the world, has received much less attention. During the late Ming and early Qing periods, most blue-and-white for foreign markets was produced in the Jingdezhen and Zhangzhou folk kilns.
Our research focuses on blue-and-white porcelain found in Southeast Asia and the first goal has been to evaluate the capability of field-deployable non-invasive technologies such as handheld X-ray fluorescence (pXRF) and fiber optics reflectance spectroscopy (FORS) in the Vis-NIR, at differentiating porcelain shards from the two aforementioned production sites. This practical approach has the potential to be very useful for on-site archaeological research and/or to sort out blue-and-white assemblages in museum collections. Following positive results obtained for a pilot study on a set of about thirty blue-and-white shards from the Philippines and Indonesia, our team is currently applying the methodology to the analysis of many more samples from the Philippines, Taiwan, Cambodia and Indonesia as well as from folk kilns in China. Beyond the identification of raw materials, sources and technical ‘savoir-faire’ as well as of compositional variations across time and space, this research aims at fostering our understanding of production processes, trade organization and consumption patterns in different archaeological and historical contexts in East and Southeast Asia.
Our research project is implemented in close collaboration with the National Museum of the Philippines, the Michigan University, the National Taiwan University, and the École Française d’Extrême-Orient. Recently, the research has also been extended to the study of Japanese blue-and-white porcelain which substituted the Chinese products in overseas markets during the period of maritime ban in the early Qing dynasty.