Instructions
Weigh the blue and white pottery in your hands. Bone China is heavier than porcelain. Knowing what the pottery is made of will help you identify its maker.
Look at the color on the blue and white pottery. Note if it is light or dark in color. Dark blue shades only indicate the pottery is older than 1805 while lighter shades of blue indicate it was made after 1805.
Turn the piece of blue and white pottery over and look at the mark on the underside. Many times the manufacturer left an engraved symbol, a stamp or a painted name to indicate who made it.