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. 24 shown for “2c Black on Buff Paper Adams' City Express Post Single” — 64 records examined, 6 dropped by the rights gate.
Archives queried 2026-08-31 19:53 UTC · fetched live for this request
isPublicDomain field is true for this object.metadata_usage.access reads CC0 — a waiver, not an expired term.
Oedipus and the Sphinx
Gustave Moreau · 1864
2c Black on Buff Paper Adams' City Express Post Single
Artist not stated in the record · 1850-1851
The Jabach Family
Charles Le Brun · ca. 1660
25c Black on Pink Paper Adams & Co.'s Express Single
Artist not stated in the record · 1854
The Rehearsal of the Ballet Onstage
Edgar Degas · ca. 1874
2c D.O. Blood & Co. City Despatch Post forgery single
Artist not stated in the record · 1843
The Forest in Winter at Sunset
Théodore Rousseau · ca. 1846–67
5c Documentary Express revenue stamp single on Adams Express Company’s receipt
Artist not stated in the record · February 6, 1863
Circus Sideshow (Parade de cirque)
Georges Seurat · 1887–88
2c Post Office Department single
Artist not stated in the record · 1873
The Penitence of Saint Jerome
Joachim Patinir · ca. 1515
2c Empire State Express train vignette plate proof sheet
Bureau of Engraving and Printing · May 1, 1901
The Crucifixion with Saints and a Donor
Joos van Cleve · ca. 1520
2c Empire State Express train frame plate proof sheet
Bureau of Engraving and Printing · May 1, 1901
Ia Orana Maria (Hail Mary)
Paul Gauguin · 1891
2c Statue of Freedom Newspaper and Periodical imprint single
Artist not stated in the record · 1875
Portrait of a Carthusian
Petrus Christus · 1446
Express from Richmond to Louisville posted to Boston cover
Artist not stated in the record · August 17, 1861
The Crucifixion; The Last Judgment
Jan van Eyck · ca. 1436–38
Express from Richmond to Louisville posted to New York cover
Artist not stated in the record · August 8, 1861
Basket of Flowers
Eugène Delacroix · 1848–49
Boyd's City Express Post mailbox
Artist not stated in the record · 1844 - c. 1860
Night-Shining White
Han Gan · ca. 750
2c Andrew Jackson single
Archer & Daly · 1863
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. 79 matched · 24 examined · 3 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. 1276450 matched · 40 examined · 3 dropped by the rights gate. Kept only where metadata_usage.access === "CC0" and an image resource was published.12 shown
These figures describe the pass run at 2026-08-31 19:53 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.