Krater

A krater was a vase used to mix wine and water. At a Greek symposium, kraters were placed in the center of the room. They were quite large, so they were not easily portable when filled. Thus, the wine-water mixture would be withdrawn from the krater with other vessels. In fact, Homer 's Odyssey describes a steward drawing wine from a krater at a banquet and then running to and fro pouring the wine into guests ' drinking cups. An interesting sidenote to this is that the modern Greek word now used for undiluted wine, krasi, originates from this mixing of wine and water in kraters. Kraters were glazed on the interior to make the surface of the clay more suitable for holding water, and possibly for aesthetic reasons, since the interior could easily be seen.

The column krater - This form was invented in Corinth, but was taken over by the Athenians, where it is typically black-figure.

The calyx krater - Probably invented by Exekias in about 525 B.C., this form remembers the calyx of flowers, with low handles protruding from the base of the bowl.

The volute krater - An Attic shape (whose handles look like the volute of a capital) that lasted through the 4th century B.C.

The bell krater - This form looks like an inverted bell. All bell kraters are red-figure.

Column Krater

Volute Krater

Calyx Krater

Bell Krater

Source:  http://en.wikipedia.org/wiki/Krater