Old Sheffield Plate is the term used to denote articles made of copper with a thin silver by fused to the copper. This process, which was invented Thomas Boulsover in 1742, ceased following the introduction of much cheaper silver-plating by electro-deposition (EPNS) about the middle of the 19th century. Old Sheffield plate was used in the production of hollow ware and flat ware. It can be distinguished from the later EPNS items because when the sheet was rolled it was soldered together with silver. The soldering line is visible. Also where the leading wedge of the sheet is visible a border of finely pressed sterling silver was soldered on to hide the copper. In later pieces an engraving plate was also set into the body of the item so that when an engraving was applied no copper would be visible. Items of Old Sheffield plate should be cleaned with care because excessive rubbing will eventually expose the underlying copper layer. In Old Sheffield plate connoisseurs circles exposed copper is not an issue. This adds character to the item. It is highly recommended that the item not be silver plated. Unlike EPNS, Old Sheffield plate used pseudo hallmark punches and makers marks on the items which have been well documented and makes them easy to date.
E.P.N.S.
Electroplated nickel silver or E.P.N.S. was introduced c.1845. It was a process of making articles with a nickel-silver base alloy and then silver plating them. Because the base metal of E.P.N.S. had a similar colour to silver, this processes became more popular than use of a copper base for Old Sheffield Plate which tended to show its coppery brown base colour as its silver coating wore off.
E.P.B.M.
Electroplated Britannia metal (E.P.B.M.) was introduced c.1875 and was considered to be the poor man’s silver ware. The base metal was Britannia metal, which was an alloy of lead and tin closely allied to pewter. E.P. B.M. has one great disadvantage. It is very susceptible to damage by applied heat. Consequently, if an article of E.P.B.M. is brought in for repair, it will not take any applied heat without damage.