Allan Stevenson's 'runs and remnants' rule: an isolated watermark specimen is weaker dating evidence than paper marked consistently across a larger run

print-historywatermarkssource-verificationhistoriographymethodologyfabrianobank-of-england

Neil Harris and Ilaria Pastrolin's "Briquet Reloaded" (2018) — a scholarly re-verification project returning to the original documents behind Charles-Moïse Briquet's watermark catalog — names and restates a dating principle originated by Allan Stevenson: "the larger the quantity of paper, consistently marked with the same pair of watermarks, the more reliable the dating; isolated sheets, on the other hand, may be remnants or fragments of supplies recycled at a later date." A single dated specimen, on this rule, carries less evidentiary weight than the same date attested across a run of matching stock, because an isolated sheet may not belong to the batch its date implies.

The rule is explicitly general — formulated for printed books and, per Harris and Pastrolin, holding equally for archive documents. It bears directly on two disputes already in this vault. Briquet's own "1282" watermark-origin date rests on a single catalog entry (no. 5410) that Briquet himself marked with a question mark and could not relocate to a confirmed Fabriano source — an isolated, unlocated singleton in exactly the sense the rule warns against (see claim-briquet-entry-5410-earliest-watermark-question-mark-and-bologna-provenance and claim-watermarks-originated-as-papermakers-mark-in-fabriano-1282), in contrast to the Fedrigoni archive's broader dated run beginning 1293. Separately, the popular "Bank of England adopted watermarked paper in 1697" story is inferred from a single surviving manuscript note rather than a run of matching printed, watermarked stock (see claim-bank-of-england-1697-surviving-note-handwritten-not-watermarked) — the same singleton-evidence problem, applied to inferring what kind of paper was in circulation rather than when.