OLD SHEFFIELD PLATE

Stumbled upon by chance, this ingenious material was a more affordable option than solid silver, and well-preserved examples are particularly desirable today

- Janet Gleeson

Imagine you're a well-to-do homeowner three centuries ago. You long for a silver candelabra to bring elegance to your dinner table and impress your guests, but you don't want to break the bank. Old Sheffield Plate is the answer.

Invented in the 1740s, using a fusion of layered copper and silver, OSP - as it's often termed - cost far less than solid silver and brought aspirational households a dash of aristocratic grandeur at a fraction of the cost. It allowed the wealthy to order large items, such as urns and wine coolers, to affordably match the other silver on their table, and spawned a lucrative new industry for enterprising craftsmen.

The revolutionary development of this material is said to have happened by accident. For centuries, craftsmen had practised the art of covering base metal with silver; but, according to legend, it was only in 1743 when Sheffield cutler Thomas Boulsover was repairing a customer's knife that a commercially viable breakthrough was made.

The knife on Boulsover's workbench had an expensive silver handle, with copper inlaid decoration. In his efforts to repair it, the cutler accidentally overheated the handle and the silver began to melt. Once the knife cooled, however, Boulsover realised that it wasn't a total disaster (although the customer may have thought differently) because the two metals had fused into one.