Helen Frankenthaler, the lyrically abstract painter whose technique of staining pigment into raw canvas helped shape an influential art movement in the mid-20th century, and who became one of the most admired artists of her generation, died on Tuesday at her home in Darien, Conn. She was 83.

Her longtime assistant, Maureen St. Onge, said Frankenthaler died after a long illness but gave no other details.

Known as a second-generation abstract expressionist, Frankenthaler was married during the movement’s heyday to the painter Robert Motherwell, a leading first-generation member of the group. But she departed from the first generation’s romantic search for the “sublime” to pursue her own path.

Refining a technique, developed by Jackson Pollock, of pouring pigment directly onto canvas laid on the floor, Frankenthaler — heavily influencing the colorists Morris Louis and Kenneth Noland — developed a method of painting best known as Color Field. Where Pollock had used enamel that rested on raw canvas like skin, Frankenthaler poured turpentine-thinned paint in watery washes onto the raw canvas so that it soaked into the fabric weave, becoming one with it.

Her staining method emphasized the flat surface over illusory depth, and it called attention to the very nature of paint on canvas, a concern of artists and critics at the time. It also brought a new, open airiness to the painted surface and was credited with releasing color from the gestural approach and romantic rhetoric of abstract expressionism.

Frankenthaler more or less stumbled on her stain technique, she said, first using it in creating “Mountains and Sea” (1952). Produced on her return to New York from a trip to Nova Scotia, the painting is a light-struck, diaphanous evocation of hills, rocks and water. Its delicate balance of drawing and painting, fresh washes of color — predominantly blues and pinks — and breakthrough technique have made it one of her best-known works.

She later described the seemingly unfinished painting — which is on long-term loan to the National Gallery of Art in Washington — as “looking to many people like a large paint rag, casually accidental and incomplete.”

Although Frankenthaler rarely discussed the sources of her abstract imagery, it reflected her impressions of landscape, her meditations on personal experience and the pleasures of dealing with paint. Visually diverse, her paintings were never produced in “serial” themes like those of her Abstract Expressionist predecessors or her Color Field colleagues like Noland and Louis. She looked on each of her works as a separate exploration.

There is “no formula,” she said in an interview in The New York Times in 2003. “There are no rules. Let the picture lead you where it must go.”