Editing Old Sheffield Plate (section)

{{short description|Fusion of copper and sterling silver}}
{{Use dmy dates|date=July 2021}}
{{Use British English|date=July 2021}}
[[File:Old Sheffield Plate Pair of Salts.jpg|thumb|302x302px|OSP Pair of table salts, the interiors gilded to prevent corrosion. 'Bleeding' of the copper can be seen on the rims.]]
'''Old Sheffield Plate''' (or OSP) is the material developed by Thomas Boulsover in the 1740s, a fusion of copper and [[sterling silver]]<ref name="Hughes">{{cite book |last=Hughes |first=Bernard|title=Sheffield Silver Plate |publisher=Praeger Publishers |year=1970 |lccn=72114296 |pages=39-42}}</ref> which could be made into a range of items normally made in solid silver.<ref name="crosskey">{{cite book |last=Crosskey |first=Gordon |title=Old Sheffield Plate: A History of the 18th Century Plated Trade |publisher=Treffrey Publishing |year=2013 |isbn=978-0-9568003-1-2 |edition=2nd |location=Sheffield, England}}
</ref>  The material rapidly gained popularity as a substitute for solid silver, as it was much cheaper to produce. Any object made in silver could be made in Old Sheffield Plate, although objects subject to heavy wear such as spoons and forks were not so satisfactory in plate. 

The characteristic identifying feature of OSP is the 'bleeding' or 'show through' of the copper base,<ref>{{cite book |last=Helliwell |first=Stephen J. |title=Understanding Antique Silver Plate |publisher=Antique Collectors' Club |year=1996 |isbn=1-85149-247-X |location=Woodbridge, Suffolk, UK |pages=131}}</ref> especially on points of wear although there is also a subtle difference in colour from the pure silver of electro plating to the "very faintly bluish lustre" of OSP.<ref>{{cite book |last=Hughes |first=G. Bernard |title=Antique Sheffield Plate |publisher=B T Batsford |year=1970 |isbn=0-7134-0723-9 |location=London |page=15}}</ref> In addition to having a distinct bluish cast, the alloy produced in OSP is also harder than electrodeposited silver.<ref>{{cite book| title=
History of Old Sheffield Plate: Being an Account of the Origin, Growth, and Decay of the Industry, and of the Antique Silver and White Britannia Metal Trade, with Chronological Lists of Makers' Marks and Numerous Illustrations of Specimens| last=Bradbury | first = Frederick| publisher = Macmillan and Company, limited | year = 1912}}</ref> The material remained popular until being replaced by the electroplate process in the 1840s.

Items produced in Old Sheffield Plate included [[button]]s, caddy spoons, [[fish slice (kitchen utensil)|fish slices]], serving utensils, [[candlestick]]s and other lighting devices, coffee and [[tea set]]s, [[Dishware|serving dishes]] and [[tray]]s, [[tankard]]s and [[Pitcher (container)|pitchers]] and larger items such as soup [[tureen]]s and hot-water urns.

'Old Sheffield Plate' with all three word capitalised is the accepted term in the antiques trade for this material. The expression 'Sheffield plate' and all variations thereof are generic terms which may apply to any product of silver appearance made in Sheffield, UK.<ref name=":0">{{cite book |last=Frost |first=T. W. |title=The Price Guide to Old Sheffield Plate |publisher=Antique Collectors' Club |year=1971 |location=Woodbridge, Suffolk, UK |page=1}}</ref>