Paul Coremans proved van Meegeren's 'Vermeers' were forgeries by finding 20th-century synthetic resins in the paint

The Belgian chemist Paul Coremans led the scientific examination that independently confirmed Han van Meegeren's courtroom confession. Rather than judge the paintings by connoisseurship — brushwork, style, provenance — Coremans analyzed their material composition: van Meegeren had mixed his oils with phenol-formaldehyde resin (Bakelite) as a modern binding medium, so the paint would harden and crack like centuries-old work, and the commission demonstrated its presence throughout the contested paintings with sulphuric-acid and ammonia discoloration tests. Phenol-formaldehyde was not invented until 1907, so its presence made a genuine 17th-century origin physically impossible: a Vermeer could not contain a substance that did not yet exist (verified at Tier 2 against Tummers & Erdmann 2022, doi:10.1007/978-3-030-86865-9_1, open access). [unverified-detail — the second resin name "Albertol" and the capture's "paint hardener" characterization appear only in the Tier-4/5 summary; a full read of the Tier 2 Tummers & Erdmann 2022 chapter (2026-07-29) finds no mention of "Albertol" either, and the 1949 primary remains untread] Coremans published the analysis in Van Meegeren's Faked Vermeers and De Hooghs: A Scientific Examination (1949, Meulenhoff/Cassell).

The method is the analytic complement to the confession: van Meegeren proved his authorship by demonstration (painting a new fake), while Coremans proved it by anachronism — an ingredient that could only postdate the claimed date. This "the material betrays the date" test is the chemical cousin of the physics-based dating covered in claim-thermoluminescence-dating-became-a-commercial-antiquities-forgery-detector, and of the "too clean to be real" statistical forensics in claim-hirsch-forensics-drove-dias-superconductivity-retraction. All three authenticate an object or result against its own origin claim, the same act that founded document authentication in claim-mabillon-1681-founded-diplomatics-to-refute-forgery-charge.