With her copper green face and unfinished background, The Chinese Girl was never an obvious masterpiece. But cheap copies of this obscure portrait by a Russian artist were once so popular that it became one of the bestselling prints of all time.Now, the original painting by Vladimir Tretchikoff, painted in 1951, is to be sold at an auction in London. It is the first time it has come to the market since it was bought by Mignon Buehler, the teenage daughter of a businessman, at an exhibition at Marshall Field's department store in Chicago. In 1954, she paid $2,000; on Wednesday, Bonhams expects it to fetch up to half a million pounds. The stories of the painting and its mass-produced copies couldn't be more different.After Buehler bought it, The Chinese Girl hung in her dining room for 20 years. In the 1970s, she gave it to her daughter, who took it with her wherever she lived. Her flatmates hated it so much they banned her from hanging it in the sitting room, and forced her to keep it in her bedroom. When her Arizona home was twice burgled, the intruders gave the same assessment both times, tiptoeing straight past.Across the Atlantic, meanwhile, the work had a much better reception: Woolworthsframed prints sold in their millions, often to be hung next to the flying ducks of suburbia. Because the print was never sold in America, Buehler remained unaware of its popularity, but in the UK, Australia, Canada and South Africa, it became an icon of kitsch, and has featured in books on retro art.Vladimir Tretchikoff was born in Moscow in 1913 and claimed to be descended from Siberian landowners, ruined by the Russian revolution. His colourful paintings went down well with the colonial set, and, in 1938, Tretchikoff represented Malaya at the New York World's Fair, hanging alongside the Bloomsbury artist Duncan Grant. He was fascinated with exotic-looking young girls, and he would scout for suitable models near his studio.One of these was Monika Pon. Being young, half-Chinese and half-French , she was ideal. She sat for almost two weeks, and still lives in Cape Town today. She recently said she was paid the equivalent of £6. "I was so stupid, so young. What did I know about business" ? Tretchikoff included her portrait in an exhibition in Durban, which caught the eye of some visiting Rosicrucians, who invited him to exhibit in their gallery in San Diego.In a bizarre twist, just before Tretchikoff left for America in 1953, someone broke into his storeroom and slashed a dozen of his works. In his autobiography, Tretchikoff claimed that The Chinese Girl had been among them, and that he had painted it again on arrival in America. But research conducted by Boris Gorelik for a new biography of Tretchikoff, to be published here this summer, suggests the American work was in fact the original."I looked through reports of the slashing of the paintings in Durban newspapers from the time, and they give a complete list of the paintings that were slashed. The Chinese Girl wasn't among them." Why Tretchikoff would later claim it was is unknown. The first prints of The Chinese Girl became available in Britain in 1956, selling for £2 each, the equivalent of about £30 today.The question is, why were they so popular? "I think they matched people's expectations of the exotic," suggests Gorelik. "In the 1950s and ‘60s, people wanted to travel to foreign lands. Like rock musicians, who have a certain period when what they do matches popular taste — this is what happened with Tretchikoff. Somehow, he reflected their hopes and aspirations."The Independent