Refined Iron-Rich Clay Slip: the Finest Fraction Settled Out for Black Gloss

The black gloss of Greek vases is a slip of the same iron-rich clay as the pot, made only of its finest particles. Fired in three stages, oxidising, reducing and reoxidising, it stays glossy black while the body turns back to red. Stir the clay in water, let the coarse part settle, and keep only the finest. The picture: our diagram, clay in water, coarse settled, fine slip kept.