What is the chain-line spacing, and does it match any impression already recorded in the census?

Chain lines are the widely spaced lines left in laid paper by the mould's supporting wires. Their spacing is a property of the individual mould, so it is a fingerprint of a batch of paper in a way that “laid paper” is not. Where a watermark is missing or fragmentary, chain-line spacing is sometimes the only measurable feature of the sheet — and unlike a watermark, it is present across the whole sheet, so trimming rarely removes it entirely. It is also a good student project: the measurement is straightforward once the image exists.

None. Laid structure has not been observed; even the claim that the support is laid paper is currently an assumption rather than an observation.

• 1Physical observationNo conservator examination has taken place · 2026-08-12

1. 01Measure chain-line intervals from the transmitted-light image, at several points, recording the range rather than a single figure.
2. 02Record the laid-line density in the same image.
3. 03Publish the measurements in a standard form so other holders of impressions can compare theirs — the value of this measurement is entirely in its comparability.

Measurements taken from a transmitted-light image, published in a comparable format.

• Paper fingerprint template

• RQ-04Does the sheet carry a watermark, and can it narrow the period in which this impression was printed?