This may be the handiest, simplest tool ever for the metal clay artist! On one side, dip your brush in distilled water, then, using the other side, wick away excess water with the sponge. Ensures the correct amount of water and prevents over-hydration of metal clay. Works great for wet or dry clay, greenware, assembling parts, keeping metal clay snakes hydrated during assembly or making your own slip or paste. We recommend using distilled water when working with your metal clay projects. Replacement sponges available.