Old Plate Mark — Pseudo-Marks on Old Sheffield Plate
Old Plate Mark — Pseudo-Marks on Old Sheffield Plate
The maker's marks applied to fused-silver plate produced in Sheffield from 1743 until the rise of electroplating
Old plate mark refers to the maker's marks and pseudo-hallmarks applied to Old Sheffield Plate — the silver-plated copper produced by fusing a thin sheet of sterling silver to a copper ingot and then rolling and working the bonded sandwich. The technique was discovered by Thomas Boulsover of Sheffield in 1743 and dominated the production of decorative silver-plated objects in Britain from the mid-eighteenth century until the diffusion of electroplating in the 1840s. Because Old Sheffield Plate was not solid sterling silver, it was not legally entitled to the formal hallmarks of the assay offices, but Sheffield makers nonetheless applied identification marks to their pieces — partly to compete with the prestige of hallmarked sterling, and partly to identify the maker for warranty and reputation purposes.
The technique
Old Sheffield Plate began with a thick copper ingot to which a thinner sterling silver sheet was bonded by fusion under heat and pressure. The bonded billet was then rolled to the desired thickness, with the silver layer maintaining its proportional position throughout the rolling. The resulting sheet had a substantial copper body with a continuous sterling silver skin on one or both faces. Worked into hollowware, candlesticks, trays, and decorative objects, the material gave the visual character of solid sterling silver at a fraction of the material cost. The seam where two sheets were joined remained visible as a fine line on the finished piece — a diagnostic feature that distinguishes Old Sheffield Plate from later electroplate.
Marks and identification
The Sheffield Assay Office, established in 1773, was forbidden from applying the regular hallmarks to plated wares, but Sheffield makers from the 1770s onward applied identification marks to their plate. These took several forms: maker's initials in shaped cartouches, sometimes accompanied by symbols (a crown, a bell, a thistle); pseudo-hallmarks resembling the formal hallmarks but distinct enough to be technically legal; and the term SHEFFIELD or SHEFFIELD PLATE stamped on the piece. From 1784, an Act of Parliament required Sheffield platers who marked their wares to register their marks at the Assay Office and to use distinct mark-shapes that could not be confused with sterling hallmarks. The registered marks survive in the Assay Office archives and are reproduced in standard reference works.
Distinguishing Old Sheffield Plate from electroplate
From the 1840s, electroplating displaced fused plate as the standard technique for silver-plated wares. The two techniques produce visually similar finished objects but are quite different in their material structure: fused plate has a continuous sterling silver layer of meaningful thickness (typically 1/24 to 1/12 of the total cross-section), while electroplate has a much thinner deposited silver coating, often only a few microns. As the silver wears through over decades of use, fused plate reveals the underlying copper as a warm pinkish glow at high points and edges, while electroplate reveals the underlying base metal (usually nickel-silver or copper) more abruptly. The visible seam at sheet joints is also diagnostic of fused plate.
The marks differ as well: Old Sheffield Plate uses the registered Sheffield maker's marks of the period 1773-1855, while early electroplate carries the marks of firms such as Elkington, Mappin and Webb, and other electroplating manufactories.
Significance for antique collectors
Old Sheffield Plate is a recognised category in the antique silver market, valued for its historical significance and the craftsmanship of the eighteenth and early nineteenth centuries. Pieces in good condition, with original silver layer largely intact and clear maker's marks, command premium prices. Collectors and dealers consult standard references including the work of Frederick Bradbury for the identification of Old Sheffield Plate marks. The Victoria and Albert Museum holds substantial Old Sheffield Plate collections.