From "The Forger's Spell - A True Story of Vermeer, Nazis, and the Greatest Art Hoax of the Twentieth Century" by Edward Dolnick

The subject is Han Van Meegeren, Vermeer forgery artist:

The second problem with the close-copy strategy was subtler, and it applied not only to Van Meegeren but to forgers generally. The closer a forger comes to getting an imitation exactly right, the more the experts grow uneasy, even though they almost certainly cannot articulate what the trouble is.

Curiously, the best analysis of the forger's dilemma comes not from the world of fine art but from the realm of robot design and video graphics. The writer Clive Thompson spelled out the problem in a brilliant article called "Why Realistic Graphics Make Humans Look Creepy." "In 1978," Thompson wrote, "the Japanese roboticist Masahiro Mori noticed something interesting: The more humanlike his robots became, the more people were attracted to them, but only up to a point. If an android became too realistic and lifelike, suddenly people were repelled and disgusted."

People liked R2-D2 and C-3PO. No one cared that they looked as much like vacuum cleaners as like human beings. To be 50 percent humanlike was fine. "But when a robot becomes ninety-nine percent lifelike," Thompson went on, "so close that it's almost real; we focus on the missing one percent." Something about the skin strikes us as wrong; the dead eyes make us cringe; the herky-jerky movements turn us off. The once-appealing robot suddenly looks like a mechanized zombie. "Our warm feelings, which had been rising the more vivid the robot became, abruptly plunge downward. Mori called this plunge 'the Uncanny Valley,' the paradoxical point at which a simulation of life becomes so good it's bad."

Van Meegeren had never heard of robots, but he had stumbled on the same insight as the Japanese scientist. At some point he realized that if he tried to fool connoisseurs with a near-twin of a real Vermeer, he, too, might fall into the Uncanny Valley. Every human is an expert on what real faces and bodies look like, and when something is close but not quite, we know it immediately, and we recoil. Connoisseurs are experts on paintings, and they, too, instinctively recoil from near-misses.

For would-be forgers, the Uncanny Valley concealed an additional, though closely related, danger. It was not simply that a close copy inevitably looked a bit off. More important, it looked off in a particular way - it lacked psychological subtlety. If Vermeer had painted only still-lifes or landscapes, perhaps Van Meegeren could have gotten away with straightforward imitations more easily. But one of the qualities we esteem in Vermeer is his genius for conveying character. A close-but-not-quite imitation will not bring us close to those psychological depths. On the contrary, we will end up dismayed and uneasy, but not sure why.

A painter who wants to involve viewers emotionally needs to leave us some work to do ourselves. Once having collaborated, we find ourselves hooked.

Artists figured it out long ago. A painstaking. seemingly perfect depiction of reality has its charms, the art historian E. H. Gombrich explained, but a painting that contains less hard "information" may nonetheless seem more real and more compelling. The reason is the Uncanny Valley again. Gombrich cites a Manet oil of horses thundering down a track, all blur and commotion and energy. "No wonder," says Gombrich, "that the greatest protagonist of naturalistic illusion in painting, Leonardo da Vinci, is also the inventor of the deliberately blurred image."

Nor is it only great artists who have learned that less is more. Jonathan Franzen points out that "an old shoe is easier to invest with comic personality than is, say, a photograph of Cary Grant. The blanker the slate, the more easily we can fill it with our own image. The most widely loved (and profitable) faces in the modern world tend to be exceptionally basic and abstract cartoons: Mickey Mouse, the Simpsons, Tintin, and, simplest of all - barely more than a circle, two dots, and a horizontal line - Charlie Brown."

Now consider where this left Van Meegeren. A genius like Vermeer can conjure up psychological depths. An illustrator like Charles Schulz. Charlie Brown's creator, can draw a rudimentary line or two and trust viewers to supply the depth for themselves. But imagine the plight of a forger chasing a genius. He has set himself a goal he cannot reach, and the closer he comes, the further he falls short.

For Van Meegeren, the moral was clear. The close-copy strategy carried enormous risk. Instead, like robot builders and video designers but decades ahead of his time, he opted for the 50 percent solution-he would do 50 percent of the work toward creating a Vermeer, rather than 99 percent, and let his eager viewers collaborate in building their own trap.