According to the expression, people only ever talk about bad forgeries because the good ones are still hanging on the wall. The announcement this month by London's National Gallery that it plans to stage its first-ever exhibition dedicated exclusively to copies and imitations gives the saying a whole new meaning. The exhibition, titled Close Examination: Fakes, Mistakes and Discoveries, to be held next June, will feature high-profile forgeries once attributed to the likes of Holbein and Rembrandt and capable of duping some of the art world's most respected experts.
The exhibition marks a departure from the usual reticence of curatorial institutions to admit to potentially embarrassing mistakes and shows the extent to which attitudes to fakes have changed. The infamous Holbein forgery Man with a Skull, acquired by the National Gallery in 1845, resulted in a scandal that caused Sir Charles Lock Eastlake to resign his position as keeper of the gallery. Today, its director, Nicholas Penny, believes that showcasing blunders is an important aspect of art history and that fakes are a valid staple of any holding.
The exhibition curator Betsy Wieseman is quick to point out, however, that Close Examination is categorically "not an exhibition promoting the creation of fakes". "Out of around 40 paintings to be displayed in the exhibition, only four or five will relate in some way to the question of fakes," says Wieseman. "The study of fakes does, however, have an important role to play in major art institutions like the National Gallery. On one level, they provide important information which helps our experts to identify the often subtle differences between authentic and fake works of art. We can therefore gain a better appreciation and understanding of the original as well as the fake. Particularly skilful fakes, such as the early 20th century Group Portrait can also be beautiful and interesting in their own right, despite the fact that they are not displayed alongside authentic paintings," she said.
A number of major artists will be represented in the National's show, including Raphael, Botticelli and Giorgione, and exhibition highlights are set to include An Old Man in an Armchair, a 17th-century work attributed to Rembrandt but falsely signed and dated. Post-purchase, gallery experts noted that the overall structure, and in particular the loose treatment of the beard, fur coat and right hand, was weak. The painting is now credited to an unidentified pupil or early follower of Rembrandt; a skilled artist who was emulating his master rather than intending to deceive. Scientific analysis of the materials and the handling of the paint have convinced National Gallery experts that the painting was produced by an artist in Rembrandt's immediate circle. Significantly, the preparation of the ground layer of the canvas is unique to Rembrandt's studio.
The Virgin and Child With Two Angels, produced in the 15th century in Verrocchio's workshop, presents the viewer with a kind of whodunit. Experts suggest that at least two hands were involved in the creation of the picture, and on closer examination it becomes obvious that the angel on the left is more finely painted than the Saint John the Baptist figure on the right and indeed the infant. The gallery hopes to solve the conundrum and identify the two artists.
Elsewhere, a painting purchased by the National Gallery in 1923 as a 15th-century work is revealed to be an early 20th-century fake created in the style of Renaissance profile portraits. The deception was definitively exposed when examination and analysis revealed it was created using pigments not available before the 19th century and that the surface had been coated to simulate the appearance of age.
Art forgery is nothing new. Historically, forgeries proliferate wherever there is a commercial market for art and demand for a collectable outstrips supply. For as long as art works have been coveted, they have been forged. From Romans forging ancient Greek sculptures to an ageing Salvador Dalí licensing his own fakes by signing his name on reams of blank paper that associates would then turn into lithographs, to unauthorised prints by the graffiti artist Banksy being illicitly sold on eBay by employees of his printer - complete with a copied signature and fake authenticity stamp - forgery is big business.
The most infamous forgeries have taken place in the 20th century. All of the major institutions have been scammed. Newsweek famously quipped in 1940 that of the 2,500 paintings Jean-Baptiste-Camille Corot created during his lifetime, 7,800 were to be found in the US. Between 1915 and 1921, the New York Met purchased what it thought to be terracotta warriors - including a two-metre statue - created by ancient Etruscan artisans. The sculptures had, in fact, been forged by two Italian brothers and their sons. The family had similarly fobbed off a large bronze chariot on the British Museum in 1908 that they claimed to have found in an Etruscan fort near Orvieto.
The public's obsession with the ingenuity, romance and excitement of forgery was captured in the 20th century by the artist John Myatt. His versions of paintings by artists such as Marc Chagall, Le Corbusier, Jean Dubuffet, Alberto Giacometti, Matisse, Ben Nicholson and Graham Sutherland were sold at major auction houses including Christie's and Sotheby's. A paper trail was created by Myatt's associates to authenticate the works and lend credence to their back stories. Myatt's "genuine fake" paintings now sell for up to £45,000 (Dh270,812) and a film about his life is under negotiation.
Forgery, however, hasn't always been seen in business terms. For many centuries, copying another artist's work was neither intended to deceive nor motivated by the forger's financial concerns. Many old masters, including Rembrandt, taught their pupils by getting them to copy works in their style. In return for this tuition, the teacher was then allowed to sell those works as their own, a practice that has exacerbated the difficulties of attributing works.
Today, techniques including carbon dating, pigment analysis and X-ray fluorescence all make the task of dating paintings and materials easier and more accurate. Cutting-edge technology helps experts to explore underdrawings, pinpoint the age of wooden panels and gather information from many other previously unexplored resources. These techniques have made getting away with forgery tougher, but they have also been used to prove the provenance of works previously branded forgeries. In 2004, Vermeer's Young Woman Seated at the Virginals was declared genuine, having been labelled a forgery in 1947.
Close Examination: Fakes, Mistakes and Discoveries will open up this world of scientific examination, conservation and art historical research to enable its audience to learn more about a painting's physical properties. This process can be as exciting as the painting's narrative. With the Holbein forgery, for example, dendrochronological analysis of the wood panel support was used to indicate that the painting postdates Holbein's death in 1543. It was probably painted in the 1560s or 1570s and is most definitely Flemish.
"The National Gallery was the first art gallery to have its own scientific and conservation departments and remains a world leader in the study of Old Master paintings," says Wieseman. "This exhibition will give visitors the chance to learn about some of the most interesting work carried out by the gallery in recent years. "For the public, this exhibition will reveal entirely new and exciting ways to engage with old master paintings - their conundrums, the way they were painted, who painted them, how the gallery cares for them and their significance over time."