Southeast Asia Vietnam and Thailand formed an interface between the sophisticated ceramic industries of China and maritime Southeast Asia, which lacked the raw materials or technology to produce high-fired ceramics. The history of ceramics in Vietnam and Thailand during the twelfth to sixteenth century is the adaptation of Chinese technology not only for local use but also for large-scale export, sometimes in competition with Chinese wares. The main Thai kiln sites located at Si Satchanalai and Sukhothai produced both celadons and pieces decorated with underglaze iron. Prominent among the shapes of Thai production are kendis (spouted jars) and potiches, many of which may have been used in religious rituals. Since the kilns lay close to a tributary of the Chao Phraya River, they could easily be transported to the Gulf of Thailand for export to Indonesia. Shipwrecks in the Gulf of Thailand have yielded cargoes laden with Thai ceramics. Painting in cobalt blue on a white body was introduced to Vietnam from China in the 14th century. The earliest pieces closely imitate Chinese blue-and-white, in motifs and decorative styles, but are distinguishable by their cream-colored stoneware bodies. When the Chinese court imposed restrictions on the export of Chinese ceramics during the middle of the fifteenth century, Vietnamese potters eagerly seized the opportunity to capture an overseas market. Although Indonesia, as far east as Sulawesi, and the Philippines were the main destinations, Vietnamese ceramics were also exported to Japan and to Western Asia.