He, of course, is not the first art forger. Painters have been copying the images and the styles of other artists for thousands of years. But Perenyi is perhaps one of the more prolific.
He learned to imitate an astonishing range of 19th century painters, like maritime artist James Buttersworth, known for the delicate lines on his sails.
"You have to have an incredibly steady hand to achieve that, and that's what Buttersworth was known for," said Cowan. "Even that little ship there, if you look very closely, has lines painted as fine as a human hair on it. How did you learn to do that?"
"A lot of practice," Perenyi said.
Ken also copied -- right down to the bootstraps - the equestrian paintings of John F. Herring.
But the crown jewel of his forgeries was a Martin Johnson Heade. In 1994 it went on the Sotheby's auction block as an original.
That night he took home a receipt for $650,000, to be wired to his account. It was his biggest score on one painting.
It wasn't only the paintings themselves that he forged; he learned to fake time itself. "I often like to look at the back of my paintings and hang it this way. I think this is an illusion that I like to create. How well can you make something look really old that's all brand new?"
He became an expert at faking the forensics of a painting -- weathering wooden frames, staining a perfectly new canvas to make it look old. He mimicked chalk marks left by auction houses, and recreated stamps from dealers. "That's a new stamp," he said of one.
"I make those on copy machines and then stain 'em with tea and glue 'em on there."
Even the nails he used to pin the canvas down were period.
But perhaps most important of all is his ability to replicate how oil paint cracks with age.
There are patterns (like a spider web, he says) that with heat and the right chemicals he can reproduce, like Father Time himself.
"It's an ongoing process. I'm still perfecting it today," he said.
He says "today" because he's STILL painting fakes. Only now, he sells them as fakes -- the look of the real thing, for much cheaper.
But why come clean now? It's because he almost got caught. The FBI had been investigating forgeries at the big auction houses -- Sotheby's and Christies -- and had traced a few suspected paintings back to Perenyi.
But he dodged their questions, saying he didn't know the origin of the paintings -- he had just passed them on.