Christo and Jeanne-Claude in their studio at 48 Howard Street in Manhattan.

Claes Oldenburg’s Bacon and Egg and Ice Cream and Beef Steak in Christo and Jeanne-Claude’s studio.

Claes Oldenburg’s circa-1960s Bacon and Egg and Ice Cream and Beef Steak that are inscribed to Christo from Claes is estimated to bring €40,000-60,000 in the February sale at Sotheby’s.

Gerrit Rietveld’s Hoge armchair in Christo and Jeanne-Claude’s studio at 48 Howard Street in New York.

The Hoge armchair by Gerrit Rietveld.

Cookie jars previously owned by Andy Warhol inside Christo and Jeanne-Claude’s studio at 48 Howard Street in New York.

The walls inside Christo and Jeanne-Claude’s studio at 48 Howard Street in New York were filled with works by their close circle of artist friends as well as sketches an other memorabilia related to their massive installations.

Objets and photographs displayed inside Christo and Jeanne-Claude’s studio at 48 Howard Street in New York.

Objets and photographs displayed inside Christo and Jeanne-Claude’s studio at 48 Howard Street in New York.

The walls inside Christo and Jeanne-Claude’s studio at 48 Howard Street in New York were filled with works by their close circle of artist friends as well as sketches an other memorabilia related to their massive installations.

The walls inside Christo and Jeanne-Claude’s studio at 48 Howard Street in New York were filled with sketches an other memorabilia related to their massive installations.

Objets and photographs, including one of Jeanne-Claude at the couple’s installation The Gates in New York, displayed inside their studio at 48 Howard Street.

Andy Warhol’s Jackie is displayed alongside Concetto Spaziale, Attesa by Lucio Fontana inside Christo and Jeanne-Claude’s studio at 48 Howard Street in New York.

Andy Warhol’s Jackie (1964) from the collection of Christo and Jeanne-Claude is estimated to bring €800,000-1,200,000 at auction.

A piece by Keith Haring hangs alongside works by Andy Warhol and Lucio Fontana and photos on a gallery wall inside Christo and Jeanne-Claude’s New York studio.

Lucio Fontana’s Concetto Spaziale, Attesa (1963).

A work table inside Christo and Jeanne-Claude’s studio at 48 Howard Street in New York.