AMSTERDAM.- Jacqueline de Jong, a Dutch artist who was at the forefront of a 1960s avant-garde movement that critiqued postwar capitalism, and who enjoyed a career resurgence in her last decade, died June 29 in Amsterdam. She was 85.

Her brother, Philip de Jong, said her death, in a hospital, was caused by liver cancer.

De Jong was associated with the so-called situationist international movement, which combined elements of dada, surrealism and Marxism in its condemnation of capitalism. She founded and edited The Situationist Times, a multidisciplinary journal, published from 1962 to 1967, that included essays, artwork and groundbreaking graphic design.

For many years, she was associated and romantically involved with Asger Jorn, a Danish painter and writer who was 25 years her senior and married.

But her artistic career was entirely independent of him, and, in spite of scant recognition over a long period, she continued to explore her unique artistic style for the rest of her life. She never settled on a single style, but bounced among abstract expressionism, pop art and new figuration, a movement that rejected abstraction.

De Jong had lived and worked in Amsterdam since the 1970s, and since the 1990s, she had kept a country house and studio in Bouan, in southwestern France. She was a painter, sculptor and engraver who also worked in unconventional media. One recent series of works was inspired by sprouting potatoes she found in her cellar in France; she depicted them in paintings and also made them into objects d’art and jewelry, coating them in 18-carat gold.

In 2012, the Beinecke Rare Book and Manuscript Library at Yale University acquired her papers, generating new interest in de Jong’s role in situationism. Her art was discovered and featured in several exhibitions, including a 2019 retrospective at the Stedelijk Museum Amsterdam.

“She kept that situationist spirit throughout her life,” said Jaring Dürst Britt, an owner of the Dürst Britt & Mayhew gallery in The Hague, which had worked with de Jong since 2017.

“Poking, playing, being discursive are all at the core of being in the situationist movement,” he said. “They tried with those types of interventions to poke at or frustrate society. In all of her artistic output, in whatever decade it was, you find elements of this type of interference.”

Jacqueline Beatrice de Jong was born Feb. 3, 1939, in Enschede, Netherlands, and grew up in the nearby town of Hengelo, where her father, Hans de Jong, a Dutch textile manufacturer, had a lace and stocking factory called De Jong & Van Dam.

A year after Jacqueline was born, Germany invaded the Netherlands. Hans de Jong’s company was expropriated under Nazi anti-Jewish ordinances. Her mother, Alice de Jong-Weil, escaped with Jacqueline to her native Switzerland, where they lived with her family in Zurich while Hans went into hiding in Amsterdam.

All of them survived the war and reunited in Amsterdam. Later, they returned to Hengelo, where Hans de Jong was able to get his stocking factory back. The couple’s son, Philip, was born in 1949.

In the 1950s, Jacqueline de Jong briefly entertained the idea of becoming an actor and went to London to study theater at the Guildhall School. “I absolutely wanted to be on the stage,” she told Frieze magazine in 2017. “Luckily, we can say, I failed.”

Her parents were art collectors with an avid interest in the performing arts. Through them, she met leading members of the avant-garde movement cobra, which emphasized art with childlike playfulness, bold colors and animal forms, and which derived its name from Copenhagen, Brussels and Amsterdam, the cities from which its members mostly came. Among them were Karel Appel, a Dutch expressionist painter, and Jorn, who would become de Jong’s lover and artistic confidant for a decade.

In 1957, de Jong worked briefly in Paris as an apprentice to fashion designer Christian Dior. She changed course in 1958, when Willem Sandberg, director of the Stedelijk Museum, hired her to work in the museum’s applied art department.

About a year later, she moved to Paris, where she worked as a studio assistant to Appel, stretching his canvases and cleaning his brushes. On Sandberg’s recommendation, she studied etching at Atelier 17, a workshop founded by influential printmaker Stanley William Hayter.

“That was the only official artistic training she had,” Philip de Jong said in an interview.

Nevertheless, she began to paint contorted animalistic figures and abstract works, using a technique called impasto to apply thick layers of paint to the canvas. When she was 19, she became a member of the situationist international, an anti-capitalist movement led by Guy Debord, a French Marxist theorist.

In 1962, there was a split in the movement, and Debord ejected all of the artists, including de Jong. “You know when I became a professional?” she said in an interview with T: The New York Times Style Magazine in 2021. “When I got thrown out of the Situationist.”

Part of her response was to start The Situationist Times, using it as a platform for a broad range of artists. She produced six issues sporadically over five years, until she ran out of money in 1967.

“That journal was such a huge accomplishment,” said Karen Kurczynski, an art history professor at the University of Massachusetts Amherst, who curated an exhibition, “Human Animals: The Art of Cobra,” which included works by de Jong, at the university’s art center in 2016.

“She made it when she was so young,” she said, “and working surrounded by so many of these older male artists, some of whom rejected her. She made that journal in defiance of them, really.”

After her relationship with Jorn ended in 1969, de Jong moved back to the Netherlands. She married twice, first to Dutch gallerist Hans Brinkman, whom she divorced in 1989. A year later, she began a relationship with Thomas H. Weyland, a lawyer, whom she married in 1998.

Weyland died in 2009. De Jong’s brother is her only immediate survivor.

De Jong carried on working and exhibiting after her second husband’s death, although she received little attention from critics or from the art market. “She wasn’t much concerned with being in the middle of the art world,” her New York art dealer, Ales Ortuzar, said in an interview. “She was very happy to keep moving and finding new styles and approaches to her art, with a radical fearlessness. It was only later in her life that she received so much attention.”

The turning point came in 2012, when she had a major solo exhibition at the Moderna Museet in Stockholm and Yale acquired her archives.

“At that moment, a lot of people realized, hey, this is quite an interesting figure,” said Britt, the art dealer. “People started to ask, ‘Why haven’t we paid more attention to her?’”

Curator Alison M. Gingeras included some of de Jong’s artworks in an important retrospective, “The Avant-Garde Won’t Give Up: Cobra and Its Legacy,” at the Blum & Poe gallery in New York and Los Angeles in 2015. Other exhibitions followed in Los Angeles, Brussels and Toulouse, France.

“One of the most fascinating things about her was how she continued to evolve,” Kurczynski said. “She kept staying in touch with current politics and events and channeling them through these incredibly energetic paintings and objects.”

De Jong, who was diagnosed with metastatic liver cancer in May, continued working on her art until she died, said her nephew David de Jong, a Dutch journalist and author.

“She loved every minute of the successes of the last years,” he said, adding: “She was a force of nature. We all thought she was going to live to 100 at least. She had the energy of a perennial 12-year-old, and she was very intense, and she lived intensely. She lived for art.”

This article originally appeared in The New York Times.