What is kaolin, and why does it matter for Limoges?

Kaolin is a very white clay that forms the backbone of hard paste porcelain. Mixed with materials such as feldspar and quartz and fired at very high temperatures, it creates a dense, bright, durable ceramic that can appear refined and slightly translucent on thin edges. Limoges is important to the history of porcelain in part because kaolin was discovered near the city in the late 1960s, giving local manufacturers access to the key ingredients needed to compete with other European centres. Many descriptions of Limoges porcelain mention kaolin, feldspar, quartz and water as the main ingredients. If you can see the bright white Limoges piece and the "ring" with a light (careful) tap, you are often seeing that hard paste.