Identify an antique piece of Josiah Wedgwood & Sons china by its maker's mark located on the bottom of the piece. Depending upon the date of manufacture, authentic Wedgwood marks are either impressed into the pottery itself, handwritten or painted on. A visual list with date ranges for Wedgwood maker's marks is available at Antique-marks.com. For pieces made after 1860, a three-letter code impressed on the bottom of the piece identifies the month, maker and year of production.
Josiah Wedgwood began using unique maker's marks on his products in 1759. However, collectors and antique dealers note several potential issues in attributing a piece to Josiah Wedgwood & Sons. For example, any mark containing & CO belongs not to Josiah Wedgwood, but to Wedgwood & CO, which became Enoch Wedgwood Ltd in 1965. Other markings which indicate possibly inauthentic Josiah Wedgwood & Sons pieces include an extra E interposed between the G and the second W in Wedgwood, or the mark W S & CO. These marks indicate potential Josiah Wedgwood & Sons fakes.
ThePotteries.org provides a guide for deciphering the three-letter codes on Wedgwood pieces manufactured after 1860 in addition to a list of other companies that used the Wedgwood marks.