Research
What is being worked on, and what it rests on
Surfaces
Open questions
Scoped, answerable problems with the current evidence, the method, what would resolve each one, and the dead ends already logged.
Impression census
Recorded impressions of this plate in public collections and on the art market, transcribed from each institution's own record with the source on every row.
State atlas
What distinguishes each state, which catalogues recognise how many, and the one state that no accessible source describes.
Provenance
One documented sale and a 385-year gap, drawn to scale.
Conservation and materials
Condition as recorded, the imaging sequence and its risks, the treatment position, and the light exposure ledger.
Bibliography
The literature this record rests on, with what has been checked against the item itself and what has not.
Publications and data
Dossier versions, the gates for version 1.0, and every export.
Public API
Read-only JSON and JSON-LD over every public entity. CC0, no key.
How to use this if you already know more than we do
Take the data
The census and every other entity is CC0 and available as JSON, CSV and BibTeX. You do not need permission and you do not need to tell us. If you find it useful in something you publish, a citation helps others trace an error back to its source.
Correct the record
If a census row misstates your institution’s holding, or a state attribution is wrong, or a bibliography entry is garbled — those are the highest-value contributions we can receive, and they are credited by name.
Take a question
Several of the open questions are contained enough for a seminar paper. They come with the current evidence, the method and the dead ends, which is most of the work of starting.