The type of ceramic used for ceremonial vessels during the Kofun period, known as Sue ware, was thin-walled, lightweight and made from a fine clay. Improvements in kiln technology introduced from Korea made higher temperatures possible, and Sue pieces were fired at over 1000°C. The reducing atmosphere (lacking oxygen) produced a grey body. A natural glaze occurred in the kiln as ash from the firing process fell onto the surface of the piece and fused with it.

Sue-ware pieces were very similar to contemporary ones made in the Korean kingdom of Silla, and suggest the close contacts between Japan and mainland Asia at that time. Native potters may have copied imported foreign forms, or Korean potters may have been working in Japan.

The flared base on many of the ritual pieces replaces what had been a separate stand used with ceremonial vessels. The base is often decorated with triangular perforations or vertical slits, again taken from Silla. The Sue pieces produced specifically for use in funerals or tombs were often decorated with applied moulded figures, of boats, humans, animals and birds. The high period of Sue-ware production was in the 6th century AD, but it continued as late as the 12th century.