There were many special wine vessels for the drinking of wine, mainly made of clay or metal. An exquisite example of such a wine vessel is the kylix of Exekias (circa 540 BC), a wine cup which, in its crater, depicts the sea voyage of Dionysus to Europe. Initially, clay wine vessels were mostly painted black and later red.The art of crafting and decorating wine vessels flourished, with themes depicting scenes from harvests, wine presses, the cult of Dionysus, and, later on, from symposia. There were many categories of wine vessels such as the calyx krater; oenochoe (wine jug); kylix (wine cup); kantharos(high swung-handle wine cup); kyathos (wine dipper); psykter (wine cooler); and many others. The kraters were used for the process of krasis, in other words the mixing of akratos (undiluted) oenos with water.