Ambroise Vollard was one of the great art dealers of the 20th Century. He died in a car crash shortly before World War II and the 10,000 works of art stored in his Parisian home were said to contain, "Discoveries everywhere, valuable things, never sold nor noted, discoveries under piles of canvases, priceless, surpassing all calculation…"

Among Vollard's many legacies was a passion for print-making. An early believer in the possibilities of color lithography, Vollard worked with master printer Auguste Clot to make an album of color lithographs with artists he selected and funded. His second print project was Les Peintres-Graveurs, an edition of 100 which included a rare print of Edvard Munch's Angst, above.

No example of the intact portfolio was known to exist until Sotheby's recently discovered one, acquired by a French family in the 1920s, that will be offered at auction in London this September, with an estimate of £500,000 to £1,000,000.