In this business, one frequently hears the term “Sheffield Plate” used to describe a wide variety of pieces from different places and times. The term is often used as if it were a brand name that somehow indicates quality and age. In fact, the name Old Sheffield Plate can only properly be attributed to one particular kind of silver plate. Old Sheffield Plate, or OSP for short, is the name given to silver plate made from a fusion process in the late 18th and early 19th century, before the invention of electroplating. A brief history of silver plating may be of some help.
For as long as there has been a demand for silver, there has been a demand for a more affordable substitute. This demand increased sharply with the rise of the merchant class in the eighteenth century and in the 1740s a cutler named Thomas Boulsover invented the first reliable and economic method of silver plating. An ingot of copper and a ingot of sterling silver were fused together and then rolled out into a sheet. This sheet (one side silver and one side copper) was then used to construct the desired item using the same techniques that were used with sterling silver. The vast majority of this fusion plate was made in Sheffield and hence the name Old Sheffield Plate.
In 1840, Elkington & Co. patented a new method of silver plating known as electro-plating. In this method, an object is constructed entirely out of a base metal then the piece is coated with pure silver using a process of electrolytic deposition. The base metal is often copper or a copper-nickel alloy with the misleading name “nickel silver”. (from this we get the acronym EPNS for Electroplated Nickel Silver) Electroplating proved to be faster and cheaper than the fusion technique, which quickly became obsolete.
Fusion plate is distinctly different from electroplate in its construction but the difference in appearance can be subtle. Good old electroplate is often confused with fusion plate. A few things to look out for are: Colour, the silver on OSP is sterling and it should have a slightly bluish patina; Marks, OSP was usually not marked at all but occasionally you will find a maker’s mark. In the mid 20th century several manufactures of silver plate started using the trade names “Sheffield Reproduction” and “Sheffield” Plate” so if it has the word Sheffield stamped on it anywhere it almost certainly isn’t OSP. (refer to Bradbury’s Book of Hallmarks for some Sheffield Plate marks); Style, OSP was made as a substitute for sterling and the shapes and styles were almost identical to the sterling pieces of the same period. So if the style of the piece says 1860, it’s not OSP; Construction, there are a variety of unique construction techniques which one can use to identify Old Sheffield Plate. These can require and expert eye to recognize but the include visible seams (which get covered up with electroplating) and let-in shields (where a sheet of solid silver is ‘let-in” to the body of the piece to provide a safe place for engraving a crest or monogram).
Over the years, OSP has become scarce and as one might expect, collectible. Due to its age, a considerable amount of it has been tampered with. Like everything else, OSP wears out and when it does, people quite innocently have it re-plated. Re-electroplated, that is. This is a material alteration to the piece and like any other antique it affects the value. And don’t think that just because your piece is showing copper that it hasn’t been re-plated, people have been re-plating OSP since the mid 19th century.
If you would like to see some examples of OSP or learn more about it, just come into the shop and ask us, and remember: Sheffield Plate is not necessarily from Sheffield, and plate from Sheffield is not necessarily Old Sheffield Plate.
For more reading see History of Old Sheffield Plate, Fredrick Bradbury,and Antique Sheffield Plate, G. Bernard Hughes.