Quadruple Plate Marks: How to Identify and Date Them

The word 'QUADRUPLE PLATE' (or 'QUADRUPLE PLATED') stamped on the underside or back of silverplated hollowware/flatware, indicating a heavier electroplating process than standard 'TRIPLE PLATE' or plain plate.

• "Quadruple" does not mean the item was electroplated four separate times; it is a marketing/quality term referring to a heavier amount of silver deposited compared to standard plate, and the precise ratio was not standardized by any regulator.

This research could not confirm a government, museum, or company-archive source for 'Quadruple Plate' -- Federal Register/eCFR access was blocked in this session, the Smithsonian and Met Museum pages could not be retrieved (rate-limited/blocked), and Wikipedia articles on Rogers Brothers, Meriden Britannia, and International Silver Company did not cover the term. Only a specialist antique-reference site could be fetched directly; no independent, non-commercial confirmation was found, so quantitative claims (e.g., exact ounces of silver used) are left unverified rather than asserted.

Turn the piece over and light the mark from a low angle with a lamp or phone torch, which throws the impressed or engraved lines into relief; a printed or painted mark wants soft, even light instead. Fill the frame with the mark, then take a second shot of the whole piece. Do not clean tarnish off silver before photographing; the mark reads better dark. The app matches the mark and shape to the notes above.