Among print enthusiasts, it is the stuff of legend: “Les Peintres-Graveurs” is one of the rarest portfolios of prints ever produced and includes prized works by such artists as Munch, Bonnard, and Renoir. It was long believed that a complete set no longer existed, having been broken up and sold off in pieces. But in fact, one does—and it is going to hit the auction block at Sotheby’s next month.

The portfolio was published by one of the 20th century’s most important art dealers, Ambroise Vollard, and emerged from a private European collection, where it had remained for decades. The album, which comprises 22 works, goes under the hammer at Sotheby’s London on September 17 as the lead lot in its print sale.

Originally issued in Paris in 1896 in an edition of 100, this set was bought by a private collector in the 1920s. To date, no collector or museum has been able to amass the complete set of works from this album. The portfolio is expected to sell for between £500,000 and £1 million ($605,000 and $1.2 million).

Pierre Bonnard La petite Blanchisseuse. Credit: Sotheby’s.

Severine Nackers, the head of Sotheby’s prints department in London, called the discovery of the portfolio “astounding.” Vollard was known to split up albums and sell the prints he issued individually. So the fact that a fully intact portfolio arrived via an unsolicited inquiry made the discovery all the more special.

“The portfolio stands testament to the work of one of history’s greatest publishers, and to the history of printmaking as a whole,” Nackers said.

Among the highlights of the album is a famous motif by Edvard Munch. Angst (or Le Soir) is the first-ever color lithograph produced by the Norwegian artist who would go on to become a prolific printmaker. A variation on his most famous work, The Scream, Munch’s print from Vollard’s portfolio shows a funeral procession against an angry red sky. It was made shortly after the Scandinavian arrived in Paris, where he lived for a time. “Angst is so powerful, and has been known to achieve upwards of half a million pounds at auction in a single lot,” Nackers said.

All told, “Les Peintres-Graveurs” comprises 13 lithographs, four etchings, two color drypoints, two woodcuts, and one embossing.

Vollard was an avid collector of emerging talent and is widely credited as being responsible for raising lithography to the status of fine art. He was an early promoter of important Impressionist and Post-Impressionist artists, often when they were still relatively unknown. Vollard championed the young Paul Cézanne, Pablo Picasso, and Paul Gauguin. For Cézanne’s first major solo exhibition in 1895, Vollard bought 150 canvases, almost all of the artist’s works. Renoir once affectionately described Vollard as “my sympathetic slave-driver.”