OpenTwo archives, queried live.
Every record below comes from The Met or Smithsonian Open Access and was filtered on that archive’s own rights field before it reached this page. 23 shown for “Johann Heinrich Friedrich Ludwig Knolle” — 57 records examined, 29 dropped by the rights gate.
Archives queried 2026-09-06 16:29 UTC · fetched live for this request
isPublicDomain field is true for this object.metadata_usage.access reads CC0 — a waiver, not an expired term.
Mary Magdalene reading in the desert
Johann Heinrich Friedrich Ludwig Knolle · 1827–75
Allegorical Figural Group Depicting the "Peace of Basel"
Royal Porcelain Manufactory, Berlin, German, established 1763 · late 18th century
Madonna and Child
Johann Heinrich Friedrich Ludwig Knolle · 1830–60
Sample
Johann Friedrich Netto, German · 1798
The Jabach Family
Charles Le Brun · ca. 1660
Celebrated Authors
Jacques Llanta, 1807 - 1864 · 1833
Richter's Werke (binder's title)
Adrian Ludwig Richter · 1879
Title to the Monesteries
Artist not stated in the record
The Garter
Jean François de Troy · 1724
Christian VIII
Artist not stated in the record · n.d.a.
The Declaration of Love
Jean François de Troy · ca. 1724
Two Goats and a Kid
Johann Heinrich Roos, German, born Otterberg, Germany 1631-died Frankfurt, Germany 1685
Esther and Mordecai before King Ahasuerus (Esther 8:1- 12)
Giovanni de' Vecchi · 1536/7–1615
Monks in a Cloister
Artist not stated in the record · 1768-1839
Center table
Imperial Armory, Tula (south of Moscow), Russia · ca. 1780–85
Fraktur taufschein (Birth Certificate)
Johann Jacob Friedrich Krebs, German, active United States, ca. 1749 - 1815 · ca. 1804
Salvator Mundi
Albrecht Dürer · ca. 1505
The Tombs, Halls of Justice
Johann Gabriel Friedrich Poppel, German, born Hammer, Germany 1807-died Ammerland, Germany 1882 · 1850
Heroic Landscape with Rainbow
Joseph Anton Koch · 1824
Die Schlafenden Kinder
Johann Leonhard Appold, German, born Dennenlohe, Germany 1809-died Nuremberg, Germany, 1858 · n.d.
Virgin and Child with Saint Anne
Albrecht Dürer · probably 1519
Carl Ludwig Fernow
Artist not stated in the record
A Goldsmith in his Shop
Petrus Christus · 1449
Where these records came from.
Two archives are wired, and only two. Each one is filtered on its own rights field — never on a title match, and never on the presence of an image file.
- The Met Collection API (Open Access)Rights field:
isPublicDomain. 17 matched · 17 examined · 0 dropped by the rights gate. Kept only where isPublicDomain === true and a file URL was published.12 shown - Smithsonian Open Access API (api.si.edu)Rights field:
content.descriptiveNonRepeating.metadata_usage.access. 25212 matched · 40 examined · 29 dropped by the rights gate. Kept only where metadata_usage.access === "CC0" and an image resource was published.11 shown
These figures describe the pass run at 2026-09-06 16:29 UTC, during this request. A completed pass is kept for 24 hours and replayed for an identical search, which is what keeps repeated queries inside Smithsonian’s 30-requests-per-hour allowance. A pass in which either archive failed to answer is never kept — an outage must not be replayed as though it were a finding about the catalogue.
Wikimedia Commons and the Library of Congress are deliberately not wired. Wikimedia was confirmed, on a live query, to return CC-BY material inside the same result set as genuine public domain works, and filtering it safely has not been designed yet. loc.gov was blocked by bot detection during the source evaluation, so its rights vocabulary has never been observed — and nothing here is built on a field nobody has read.
An image file is a rights claim. It never travels without its field.