"There has not been a great Bonnard on the market in recent years, but there have been good paintings," says Di-Donna, citing the 2003 sale at Sotheby’s London of La Porte fenêtre, 1932, portraying Marthe sewing near a window, for just over £4,261,600 ($7 million) against a £3 million estimate. "If a picture like that came back up, it would [bring] in excess of $10 million today." La Porte fenêtre, which went to a private collector, is included in the Metropolitan show.

Guy Wildenstein, a principal dealer in Bonnard through his New York gallery Wildenstein & Company, concurs that it is becoming harder and harder to find the artist’s strongest pieces. Among these, the Nabis works and the great coloristic achievements of the last three decades of his life, Wildenstein states, tend to have the greatest appeal and fetch the highest prices. "Were the Musée d’Orsay’s La Partie de croquet, 1892, to be available today," he says, "or La Salle à manger à la campagne, 1913, at the Minneapolis Institute of Arts, or one of the great pictures in the Phillips Collection, each would undoubtedly sell for a price in excess of $25 million."

According to Wildenstein, sums realized for Bonnards in recent private sales have been on a par with those achieved by Matisse, a close friend of the artist’s who has been paired with him over the past two years in several museum shows at venues such as the Jardin du Tivoli, in France, and the Palazzo delle Esposizioni, in Rome. Bonnard’s auction prices, in contrast, have yet to catch up with those of Matisse, whose current record is $33.6 million, set at Christie’s in 2007 for his L’Odalisque, harmonie bleue, 1937.

Wildenstein’s observation about Bonnard’s Nabis works is echoed by Di-Donna, who says this period used to be regarded as the artist’s most important, art historically, and by Izabela Grocholski, of the Jan Krugier Gallery, in New York, who has found these pictures to be the most sought after by collectors. Bennett points out, however, that because they tend to be small, the Nabis paintings typically fetch just under $1 million. The works that break through this ceiling are relatively large. Bennett cites, for example, the 15-by-18-inch 1891 study L’Après-midi au jardin, which sold for $2.5 million in 2007 at Christie’s. La Partie de croquet, the Nabis masterpiece that Wildenstein surmised could bring upwards of $25 million, is exceptional in scale, conceived as a screen in four sections and measuring 51 by 64 inches.

Following his Nabis period, the painter began incorporating some of the naturalism of the Impressionists, says Amory, who points out that he had always been ill suited to painting from life, as most Impressionists did. Wildenstein feels that, despite their transitional character, Bonnard’s pictures from "between 1900 and 1910" are "still somewhat underappreciated." An exception, the dealer notes, is the sensational Paris cityscape Place Clichy, 1906-07, which earned $7.7 million, Bonnard’s second-highest auction price, in 2006 at Sotheby’s.

After moving to the country, in 1912, Bonnard made a habit of tacking his canvases to the wall, so he wouldn’t be distracted by anything in his field of vision. He painted what he knew most intimately — his home and wife — from his imagination and from his notebook sketches, which now sell for $6,000 and up, according to the New York dealer Jill Newhouse. "They’re really mini grisaille paintings," says Newhouse. "To get something for that price by an artist who we’re all acknowledging now is as great as Matisse is a very good value."

Amory observes that Bonnard would continually add and subtract around the edges of his works elements that were often ambiguous and underscored the flux of life. Such extemporaneous framing, adroitly employed in the later paintings, might resonate with today’s aesthetic, but the critics of 1947, when Bonnard died, were dismissive. "He was considered an Impressionist has-been," says Amory. This attitude didn’t fundamentally shift until 1984, with the French art historian Jean Clair’s groundbreaking Bonnard retrospective at the Centre Pompidou in Paris. This was followed over the next two decades by several similarly enlightening exhibitions, such as PaceWildenstein’s 1997 "Bonnard/Rothko: Color and Light," which explored Bonnard’s influence on the Abstract Expressionists; the Museum of Modern Art’s 1998 retrospective; and the 2006 Musée d’Art Moderne show mentioned above. After viewing the last, the New York Times critic Michael Kimmelman — who poetically considers Bonnard’s career in his book The Accidental Masterpiece: On the Art of Life and Vice Versa — wrote, "Beneath his sunny pictures of his wife and his garden, of summer fruit and paradisiacal landscapes, Bonnard had a Proustian relationship to memory and an equally complex syntax of perception."