German Stoneware The production and export of German stoneware reached its peak in the late 1500s. Prized for its durability and stone-like appearance, German stoneware became one of the most widely traded forms of pottery, even finding popularity in early America. The distinctive pebbly glass surface, resembling an orange peel, was achieved by introducing salt into the hot kiln during the firing process. This glaze gave clear definition to the coats of arms or other emblems that often formed the surface decoration on large works, usually jugs.