Photo attributions

Doubled Die (Obverse) — Lost Dutchman Rare Coins (photo); Victor David Brenner (coin design), Public domain · Obverse of the famous 1955 doubled die obverse Lincoln cent; dramatic doubling clearly visible in IN GOD WE TRUST, LIBERTY, and the date 1955. Verified visually.

Doubled Die (Reverse) — Jespinos, CC BY-SA 4.0 · Close-up of the reverse of a 1958 Chile 1 peso; clear doubling on UN PESO and the date 1958. No usable US DDR photo found on Commons (1969-S DDO file is only 200px).

Repunched Mint Mark (RPM) — Jespinos, CC BY-SA 4.0 · Close-up of a doubled/repunched Santiago mintmark on an 1878 Chile 20 centavos (uploader: 'double mint mark error'); two overlapping punches clearly visible. No usable US RPM photo found on Commons.

Off-Center Strike — Contactsmc, CC BY-SA 3.0 · US Lincoln cent struck approximately 40% off-center; local file matched Commons original by SHA1 and visually verified.

Broadstrike — Economicrealist (Commons uploader; no Artist field in file metadata), CC BY-SA 3.0 · Broad-struck 1999 US Lincoln cent expanded to the size of a nickel, shown next to a normal Buffalo nickel for scale; used in Wikipedia's Mint-made errors article. SHA1-matched to Commons original and visually verified.

Clipped Planchet — Jespinos, CC BY-SA 4.0 · Close-up of the clipped area on a 1934 Chile 10 centavos: the top rim shows the irregular incomplete edge where the planchet was punched from an already-punched area of the strip; denticles fade out across the clip. Non-US - no clear US clipped-planchet photo exists on Commons (the only US candidate, 'File:4 clipped off center error cents.jpg', is dominated by off-center strikes and would misteach). Companion edge-profile view exists at File:10 Centavos 1934 clip.jpg. Visually verified; 640x480.

Die Crack — Mustang Joe (Joe deSousa), CC0 · 1943 Canada 50 cents, both sides; raised die crack runs from the bottom of King George VI's bust to the rim on the obverse (right coin, ~7 o'clock). Reverse also shows light clash marks. Full-resolution original (6496x3596) kept because the crack needs the detail; crop/zoom obverse bottom for the app.

Die Cud — Uploaded to Commons by Economicrealist (no author listed; released as public domain), Public domain · 1982 Jefferson nickel with a raised rim cud at 12 o'clock obliterating the L of LIBERTY. Error clearly visible, but source image is small (519x270) - the only cud photo on Commons.

Die Break — Classical Numismatic Group, CC BY-SA 2.5 · Roman siliqua of Constantine II (CNG auction photo, described 'die break and a few marks on obverse'); prominent raised die-break ridges arc across the obverse around the portrait. No usable US die-break photo found on Commons.

Lamination Error — Patriot62371, CC BY-SA 4.0 · 1963-D Lincoln cent struck on a planchet that had already split (split planchet - the extreme form of a lamination error). Obverse is fully struck; the exposed reverse shows the rough striated delaminated metal surface characteristic of lamination. Visually verified. No photo of a partial lamination flake exists on Commons; companion image File:1963 Lincoln Cent Struck Before Split Error.jpg shows a cent that split after striking.

Wrong Planchet — Professional Coin Grading Service, Public domain · The famous 1944 steel cent: a 1944 Lincoln cent struck on a leftover 1943 zinc-coated steel planchet instead of the correct bronze planchet - a classic US wrong-planchet error. High-quality PCGS obverse/reverse photo (2200x1101), visually verified. Commons tags it Public domain; page credits Professional Coin Grading Service.

Blank Planchet — Economicrealist (Commons uploader; no Artist field in file metadata), CC BY-SA 3.0 · Two unstruck coin blanks side by side: a Type I blank (flat, no rim) and a copper Type II planchet with upset rim - exactly the blank-planchet error as it enters circulation. Visually verified; modest 493x249 scan. Larger PD alternative if needed: File:500 pesos de Mexico de 1986-1992 (cospel).jpg (crisp single Mexican blank, 1011x912).

Grease-Filled Die (Struck Through Grease) — Genesis Widick at English Wikipedia, Public domain · 2005-P Kansas State quarter reading "IN GOD WE RUST" - the T of TRUST failed to strike because the die was filled with grease. Classic grease-filled die error. SHA1-matched to Commons original and visually verified.

Die Clash — Wcarper, CC BY 1.0 · Close-up of a 1993 Lincoln cent with a misaligned die clash (MAD clash): incuse ghost outline from the reverse die visible in the field left of the date, marked with annotation arrows by the photographer. Alternative without arrows (subtler error): Smithsonian's File:1831-5C (clashed rev die) (rev).jpg, public domain.

Strike-Through — Dacoinguy, CC BY-SA 4.0 · Dropped star struck into a Kennedy half dollar obverse (compacted die fill fell onto the planchet before striking) - the image Wikipedia's Mint-made errors article uses for its Strike-through section. Extreme macro closeup; red arrow marks the dropped star. Visually verified. Only strike-through photo on Commons.