Flow Blue refers to pottery produced in Staffordshire and other parts of England by about 1820. Flow Blue pieces include bowls, coffee pots, bread tray, casserole, pitchers and plates. The flowing blue color was achieved by the reaction of chlorides upon ceramic colors. The blue color was blurred in the pieces by adding lime or ammonia to the kiln. Ornamental motifs, landscapes and historic events appear on Flow Blue pieces. Ironstone china was usually used in making Flow Blue pottery.