Because the catalog was published in 1880, while the artist was very much alive and available for consultation, Wainstein said, it's unlikely that "Paysage Bords de Seine" was painted by a follower of Renoir's rather than the master himself.
And, because the photograph matched the painting in Craner's hands down to the smallest detail — including a mark left by a historical accident — she strongly doubts that it's a forgery.
"There's even the exact same spot in the right-hand corner that looks like old fly dirt," she said.
"It isn't part of the painting itself. It was there in 1926 in this black-and-white photograph, and it's there on the painting now. That sealed the deal for me."
In addition, Craner said, because of the idiosyncratic color palette and the myriad brush strokes going every which way, this particular painting would be "a forger's nightmare."
"If I were going to forge a painting," she said, "I'd choose something simpler to copy."
Authenticating a work of art inevitably is fraught with peril. However, experts contacted by The Baltimore Sun said the Potomack Company used standard verification procedures.
For her part, the woman who found the Renoir is reeling a bit from her good luck — not to mention the media attention. In the past few days, she's been interviewed twice by the BBC. Radio stations in Finland, France and Germany are calling, and a request has just come in from Australia.
She's barely had time to think about how to spend her potential windfall, though her house could use new siding. But, she figures that someone close to her would love to see with her own eyes the river that Renoir painted.
"The first thing I'm going to do," she said, "is take my wonderful mother to France."
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