White pipe clay (Dutch: pijpaarde) is a white-firing clay of the sort that is used to make tobacco smoking pipes, which tended to be treated as disposable objects.
Such clays are not uncommon; in England they are found in the river Thames upstream from London, and in the Low Countries the clay was found in deposits of the Rhine and Meuse rivers and in the 16th-century centres of production for white pipe clay objects were Cologne, Utrecht, Liège and Gouda, South Holland.
In archaeological digs in the Netherlands, small white devotional figurines have been found, but more importantly, several recent digs in cities have uncovered the molds used to press these small figurines.
The pipes can be seen in a number of 17th-century paintings and are regularly found in archaeological digs in the Netherlands.
In the 1911 Encyclopædia Britannica, Gouda was still known for its churchwarden pipes and even mentioned a winter pastime of skating while smoking from Rotterdam to Gouda without breaking such pipes.