Agnes Martin

Agnes Bernice Martin, painter: born Macklin, Saskatchewan 22 March 1912; died Taos, New Mexico 16 December 2004.

In June this year, the American painter Agnes Martin shocked the normally unshockable clientele of her New York gallery, Pace Wildenstein, with a series of new works. Martin had for 30 years been known as a painter of stripes: horizontal bands of colour on cool, square canvases, commonly thought to reflect the wide horizons of her adopted state, New Mexico.

In her New York show, though, the nonagenarian painter abandoned the modernist grid that had shaped her work since the early 1970s and produced instead pictures of floating free-form shapes; dark rhomboids on grey backgrounds that hinted at pictorial illusion. The critic of The New York Times bravely dubbed the works in "Agnes Martin: homage to life" "retro-geometric", although his dismay, and that of other long-time Martin fans, was hard to disguise.

It was, perhaps, based on a forgivable misunderstanding of what Martin really was. Born in the same year as Jackson Pollock, she spent the final part of her long life being described as "the last of the Abstract Expressionists". Although this was an easy description to fall back on, it was not entirely true.

Martin had certainly been in at the birth of Abstract Expressionism, helping set up the artists' colony in the Lower Manhattan district of Coenties Slip with her friends Ellsworth Kelly and Jack Youngerman in the late 1950s. Unlike these men, however, Martin was resistant to what might broadly be called concept.

Studying for a degree in art education at Columbia in the early 1940s, she had gone to lectures on Eastern philosophy by D.T. Suzuki and Jiddu Krishnamurthi. These, rather than the Abstractionists' belief in narcissistic self-expression, came to shape her style. Key to this was an emphasis on simplicity of form that has sometimes led to Martin's being described, also inaccurately, as a Minimalist. Like Abstract Expressionism, Minimalism required its members to toe a party line. Martin's own line, in so far as she can be said to have had one, was personal; the geometric order of her paintings emotional rather than systematic.

There was, perhaps, something moral about this line, something monastic. One consistent feature of Martin's later work was the graphite lines that showed through her painted stripes, emphasising the fragility that held her pictures together. These lines made a virtue of humility; not a word you associate with Kelly or Youngerman, but one which Martin used frequently and which is easily used about her. One of her poems, written in 1973, stands as an ode to it:

I can see humility

Delicate and white

Humility, the beautiful daughter

Sweet, smiling, uninterrupted, free.

Her paintings, too, are self-effacing, treating all areas of the canvas equally, denying any sense of hierarchy or specialness. Martin's description of how these works came about was correspondingly low-key. "The artist searches for certain sounds or lines acceptable to the mind," she said, "and finally for an arrangement of them that is acceptable."

It is tempting to trace this taste for the simple back not to the level landscape of New Mexico, where Martin lived full-time from 1968, but to the Canadian prairie of her childhood. This is less a matter of topography than of state of mind. After the death of her father, a wheat farmer, when she was two, Martin was raised by a Scottish Presbyterian grandfather who introduced her to the book that was to remain a lifetime favourite: Bunyan's Pilgrim's Progress. It was a work to which the artist's own life was to bear a passable resemblance.

At the epicentre of modern American art and with her career in the sharp ascendant, Martin turned her back on New York and painting in 1967. Although she always refused to talk about why she had done this, it is probable that she found the growing commercialism of the Manhattan art world distasteful. One of Martin's students from the University of New Mexico at Albuquerque, where she had taught in the early 1950s, recalled passing a New York gallery in 1967 and seeing his ex-teacher waving at him through the window. Going in, he said, "Agnes, you lied to me. You told me art was fun." "I know," answered a despondent Martin. "I've been fooling myself, too".

Giving away her paint and rolls of canvas to younger artists, she abandoned her Manhattan loft and set off on a year-long trip around the American West in a pick-up truck. In 1968, Martin bought a plot of land on an isolated mesa near Cuba, New Mexico, where she built herself an adobe house with her own hands and lived in it for the next 23 years. Its sole decoration was a poster of a painting by Georgia O'Keeffe.

It was from New Mexico that she had been plucked from artistic obscurity by the lesbian gallerist Betty Parsons, in 1957. (Martin herself was claimed by queer theorists as a gay artist, although she remained as reticent about this as about everything else in her private life. "Passion is only one emotion," she said, "and a not very interesting one at that.") Now, stricken with depression, she lived there by herself, unable to paint. It was only in 1974 that Martin found the grid that would underpin her art for the next 30 years: a pattern that seemed to impose order on her own chaos.

Martin's life, both in her Cuba house and in the retirement home in Taos she moved to in 1991, followed an equally structured routine. Rising at dawn, she painted from 8.30am to 11.30am, lunched, read in the afternoon and went to bed at six. Until her mid-eighties, she stretched her own canvases; these she reduced in size from six feet square to five so that she could continue to move them herself into her nineties. Each canvas was layered with two coats of gesso, gridded with the same piece of tape and painted with watered acrylic. There is a Benedictine feeling about this process as there is about her work; an order that finds virtue in the artisanal and quiet.

In contrast to this simplicity, Martin's reputation in the last 30 years of her life took on a mythic quality. Slightly to her horror, she became a star. She was awarded the Golden Lion award at the 1997 Venice Biennale and the US National Medal of Arts by President Bill Clinton in 1998. When the Dia Beacon arts centre opened its newly expanded Riggio Galleries in Beacon, New York, earlier this year, it was with an exhibition of Martin's seldom-seen paintings from the late 1950s. (This show, "Going Forward into Unknown Territory", continues until mid-April.)

Through it all, Agnes Martin remained as simple as her work. "In my best moments," she wrote, "I think, 'Life has passed me by'; and I am content."

Charles Darwent