vessels may be decorated by shallow carving of the clay body, typically with a knife or similar instrument used on the wheel. This is common in Chinese porcelain of the classic periods. Burnishing: The surface of pottery wares may be burnished prior to firing by rubbing with a suitable instrument of wood, steel or stone to produce a polished finish that survives firing. It is possible to produce very highly polished wares when fine clays are used or when the polishing is carried out on wares that have been partially dried and contain little water, though wares in this condition are extremely fragile and the risk of breakage is high. Terra Sigillata is an ancient form of decorating ceramics that was first developed in Ancient Greece. Lithography, also called litho, although the alternative names of transfer print or "decal" are also common. These are used to apply designs to articles. The litho comprises three layers: the colour, or image, layer which comprises the decorative design; the cover coat, a clear protective layer, which may incorporate a low-melting glass; and the backing paper on which the design is printed by screen printing or lithography. There are various methods of transferring the design while removing the backing-paper, some of which are suited to machine application. Banding is the application by hand or by machine of a band of colour to the edge of a plate or cup. Also known as "lining", this operation is often carried out on a potter's wheel. Agateware: named after its resemblance to the mineral agate. Is produced by parially blending clays of differing colours. In Japan the term "neriage" is used, whilst in China, where such things have been made since at least the Tang Dynasty, they are called "marbled" wares. Engobe: a clay slip is used to coat the surface of pottery, usually before firing. Its purpose is often decorative though it can also be used to mask undesirable features in the clay to which it is applied. The engobe may be applied by painting or by dipping to provide a uniform, smooth, coating. Such decoration is characteristic of slipware. For sgraffito decoration a layer of engobe is scratched through to reveal the underlying clay. Gold: Decoration with gold is used on some high quality ware. Different methods exist for its application, including: Best gold – a suspension of gold powder in essential oils mixed with