Porcelain pierced by hand while the clay is still soft, with hundreds of small openings cut through a raised lattice, so the wall of the cup is part solid and part air. Hold it up to a lamp and the light comes through in a fine grid; fill it and the tea glows behind the pattern. The saucer is scalloped and worked with the same needle. This is decorative porcelain in the old European tradition, made slowly and, frankly, not made for the dishwasher.
