The imitation of works of art, from paintings to sculpture, has been carried out for hundreds of years. Students and followers have always made copies of the works of master artists as part of their instruction. There are many artists, both unprofessional and professional, who like to paint or draw in the style of those they admire. Art forgery, however, is different. It involves passing a copy of the artist's work off as created by the original artist, usually for financial gain.
Forgers often give themselves away even before laboratory analysis of their work begins. They often add an element of their own natural style, or they may unknowingly include some contemporary period detail that the historian will notice immediately. Art experts also comment on a "lack of freedom" to many forgeries, as the forger sometimes uses more rigid brush strokes or lines to capture details of the original work. The thought processes of a master piece creating a work of art is different from those of someone far less talented who is merely trying to imitate him or her. Often this difference will spill out into the work, although the forger may not be aware of it.
An analysis of forgery must rely on more than the expert opinion of an art historian. Laboratory materials techniques such as X-radiography and infrared reflectography help detect forgery. Recent artistic materials, like paper, inks, and paints are different in composition today from those used hundreds of years ago. The art
Cited: Page 1. The Expert versus the Object: Judging Fakes and False Attributions in the Visual Arts By Ronald D. Spencer. 241 pgs. 2. Detecting forgery: forensic investigation of document By Joe Nickell