Artists such as Van Gogh, Gauguin, Manet, Sisley, Cézanne and Renoir reached fame after their deaths and were therefore much copied.
However, it was during World War Two that forgers became extensively busy. As soon as the Germans invaded a large part of Europe, Nazi leaders enacted a plan to plunder famous oil paintings belonging to their political opponents and Jewish families. The main Nazi leader involved in the theft of old master oil paintings was Hermann Goering who formed his own extensive collection.
Goering was interested in masterpieces and was told one day that he could obtain some oil paintings by Vermeer in Holland. The Nazi leader went on to buy one of them, Mary-Magdalene washing the feet of Christ, from the art forger Hans Van Meegeren. In the 1930's, several experts, including Bredius, the best specialist for Vermeer's works, had said they had no doubts about the authenticity of this work.
At the end of the war, Van Meegeren was arrested on charges of collaborating with the Germans because he had sold Goering the Vermeers. While in prison, Van Meegeren baffled art specialists by confessing that he had in fact forged oil paintings certified as by Vermeer and sold to Goering as well as to other art collectors.
Peeved at being considered an obscure untalented artist, Van Meegeren told investigators that fooling art experts had been his revenge. He added that it had been quite exciting to fool art critics who had scorned his own works.
The war did not affect the art market for oil paintings much especially in occupied Paris where the art trade blossomed despite economic restrictions. With the return of peace, the French capital became the main art trade centre while the United States was just seeing the emergence of its modern school of painters.
The oil paintings of Picasso, Braque, Matisse, Miro, Dali were now famous and the art market was in constant development. The late sixties forgers saw the appearance of several renowned art forgers including David Stein, Elmir de Hory and Real Lessart. The former being specialised in fake Chagall, Picasso, Dufy and post-impressionist oil paintings, the latter two working for an agent called Fernand Legros who was selling his fine art reproductions with forged certificates. A former ballet dancer, Legros fooled a few rich American magnates, including Arthur Meadows, the owner of the General American Oil Co. in Texas.
Legros once used a subtle stratagem on entering American territory. When asked by U.S customs what was in his luggage, Legros explained that the oil paintings he was bringing were merely fine art reproductions. Eager to verify, U.S customs officials would call upon art experts to determine whether Legros was not trying to cheat them and driven by such suspicion, these art specialists concluded that these fine art reproductions were in fact genuine oil piantings. Unmoved by the fine imposed on him Legros would then further impress his customers by showing them the U.S customs documents proving the authenticity of the hand painted, fine art reproductions he was selling.
David Stein, who had managed one day to have a forged Picasso oil painting authenticated by the master himself, was arrested after Marc Chagall saw a forged oil painting exhibited in a New York Gallery. He later started a career as a painter after serving a prison term.
Elmyr de Hory, who lived on the island of Ibiza, made hundreds of oil painting forgeries including works signed Van Dongen. The Dutch artist , apparently in need of money near the end of his life, endorsed more than once the fakes sold by Legros as being genuine Van Dongens.
In the 1960's certain artists repudiated some of their own oil paintings because they felt dissatisfied about the quality or about the low prices at which these were sold. This was notably the case with the Italian master Giorgio de Chirico who was charged in 1969 for having seized some of his sculptures as forgeries whereas he had signed a legal contract for their production. Another master, Maurice de Vlaminck refused to authenticate some of his own oil paintings simply because he did not like them anymore. He also was charged and received a fine for having rejected an oil painting which was in fact genuine.
In England, many experts were undermined by the Keating scandal in the 1970's. Tom Keating had made a speciality of producing forged water-colours by Samuel Palmer and oil paintings by Flemish, Dutch, English and French old masters.
Keating, who came from a poor London family, failed to reach fame and therefore wanted to avenge himself by producing forgeries of oil paintings and drawings which were to be certified as genuine works by Gainsborough, Degas, Boucher, Fragonard, Renoir, Modigliani and Van Dongen.
Other artists who have been forged include Van Gogh, Boudin, Vuillard, Matisse, Léger, Braque, Utrillo, Rouault, Jean-Michel Basquiat, Franz Kline, Marie Laurencin, André Lhote, Chaïm Soutine, Modigliani and Signac. It is estimated that over 15% of paintings sold throughout the world are fakes.