Forgeries

DETECTING FORGERIES By use of special illumination such as ultraviolet black light infrared photography, and X-ray radiographs, inconsistencies and changes in paintings may be detected. Instrumental analyses may reveal anachronisms in a work of art, and techniques such as carbon-14 dating, thermoluminescence dating, and dendrochronology (tree-ring dating) are all helpful in detecting forgeries in works of art. The dates when many pigments were introduced into the artist's palette are known; thus, if the 18th-century pigments Prussian blue and zinc white appear in a painting purported to be of an earlier date, then the work is obviously a forgery. Paint extending over an old crackle pattern may be evidence of repainting. Signatures are often changed by a forger; frequently, the binocular microscope is used to detect the alteration. Radiographs will reveal changes made by the original artist as well as those made on an old object by a forger. Pottery from archaeological sites is often “restored” from pieces that do not belong together by filing down edges of similar pieces from a second object. These, and fills of plaster or other materials, may show up in the X-ray. The best detector of a false work of art however, is the trained human eye. For example, a banker who is thoroughly familiar with printed currency can detect counterfeit money just by casual scrutiny, just as a fraudulent signature on a check is glaringly obvious when compared with a true signature. The detection of forgeries should be carried out jointly by art historians, art conservators, and scientists who have specialized in analysis of art and archaeological materials.