For centuries, the town of Sheffield, England, has been synonymous with art of silver making. Dating back to the 14th century, many craftsmen worked in silver in and around Sheffield. In the mid 1700s, silver was fused to copper and called Sheffield plate.
An invention of Thomas Boulsover (1705-88), Sheffield plate was born by accident. While Boulsover was busy repairing a silver pot, he discovered a process for plating metals together. In 1740, he accidentally fused copper and silver together, which resulted in a very strong metal.
The attributes of Sheffield plate include good looks and durability. Sheffield plate is comparatively quite inexpensive when compared to sterling silver.
Shown is a silver plated antique teapot.
The stamped marks found on Sheffield Plate resemble sterling silver hallmarks showing town marks, makers' marks and date stamps. In 1773, a law was passed banning the use of hallmarks on pieces made from plate. By the 19th century, Sheffield plate pieces also were produced in Birmingham and other parts of Europe.
The process of making Sheffield plate is pretty simple: a sheet of silver is fused on top of a thicker sheet made of copper. The compound is then rolled and both metals expanded equally together to become a thin sheet of copper hosting a thin layer of silver.
A one eighth of an inch thick sheet of silver can be pressed on top of an ingot of copper making a metal sandwich. The ingot was placed inside a furnace and then allowed to cool. The copper and silver were flattened into a sheet of workable metal. By the 1750s, Sheffield plate was produced in large quantities. Thomas Boulsover produced Sheffield silver objects such as coat buttons, patch boxes, snuff boxes, etc. His market was the middle class who wanted objects that looked as good, but weren't as expensive, as those owned by the upper classes. Makers that followed Boulsover such as Joseph Hancock and Matthew Boulton produced more impressive objects using Sheffield plate such as coffeepots, teapots and candlesticks. The works of these important Sheffield silver plate makers are remarkably popular with collectors now. Today, values for original Sheffield plate objects range from the several hundreds of dollars to several thousands of dollars.
Be careful not to be overzealous when cleaning your Sheffield objects. Over cleaning Sheffield plate can reveal an object's copper core exposing the copper through the silver.
When it comes to collecting Sheffield silver plate, look for decorative objects used for table service, figural objects that have a sculptural appeal and utilitarian objects of quality and strength. Condition is key to value and quality will be exceptional as long as you have identified that you are buying an authentic piece of Sheffield silver.
Unlike Sheffield plating, the process of electroplating metal uses an electrical charge and a salt bath. Electroplating results in a fine coating of precious metal over another material using an electrochemical reaction. The process of electroplating (also referred to as electro-deposition) works when a negative charge is placed on an object to be coated. The object is then immersed into a salt solution of the metal. The negative ions of the salt are positively charged and are attracted to the negatively charged object. Once they connect, the positively charged ions revert back to their metallic form, resulting in a newly electroplated object.
Plating thickness is based on the amount of time that the object spends in the salt solution. The longer the object stays in the bath, the thicker the shell becomes. The shape of the object will affect the thickness with sharp corners plated more thickly than other areas. Why? Because the electric current in the bath will flow more densely around corners. The electroplating process is used in the jewelry, automotive, optics and decorative arts industries. Applications are infinite.
Ph.D. antiques appraiser, author, and award-winning TV personality, Dr. Lori presents appraisal events to audiences worldwide.