The Engishiki (codes and procedures on national rites and prayers) stipulated size standards for earthenware, such as the diameter of owan (large soup bowls) as 289mm, nakawan (medium-sized soup bowls) as 212mm, showan (small soup bowls) as 182mm, kaban (plates with a floral pattern with legs) as 167mm and hanagataenbai as 91mm.
延喜式には、大椀（径9.5寸）・中椀（径7寸）・小椀（径6寸）・花盤（径5.5寸）・花形塩杯（径3寸）などの規格が定められていた。