Using Sponges in Pottery CreationSponges are extremely useful when creating pottery, whether handbuilding or throwing. They hold a vast amount of water or slurry. This is valuable in transporting water to the clay when it is being worked, but even more importantly in absorbing and transferring water away from the clay, particularly in throwing. You need enough water to lubricate the clay and facilitate bonding, but not so much as to weaken the structure of the greenware as you are creating it.
Using Sponges in Decorating
The technique of spongeware probably originated in Crete 4,000 years ago. There are examples of Minoan ceramics which clearly were decorated by using a sponge to daub glaze onto the ware, resulting in a stippled effect.
Another technique was also developed in which fine-pored sponges were cut into shapes such as stars, flowers, circles and arcs. These cut sponges would be dipped into glaze or colorants, then applied to the bisqueware to create a pattern that could be repeated. The results are similar to potato printing. During the 19th century this form of decoration became fairly widespread. It was used not only by studio potters, but also in factories since the technique was quickly learned by apprentice workers.