Agnes Martin, the subject of a retrospective now at the Tate Modern, was born in Saskatchewan in 1912, and spent much of her adult life in rural New Mexico. It’s easy to draw connections between her bare, minimalist paintings to those stark landscapes, although she may have been more influenced by the zen philosophy she studied at Teachers College than by the Canadian prairie.

Her early works – paintings of biomorphic shapes, and found objects – show the influence of O’Keeffe, Miro and Johns, but she quickly found her own language of the rigid grids and bands she tinkered with for the rest of her career.

One of her most successful works is A Grey Stone (1963), a vast canvas that immediately strikes the viewer as a wall of, yes, grey. Get closer, and you see it’s a grid of tiny rectangles, hundreds or thousands of them, etched faintly into the dark paint. (Get even closer and you set off an alarm. Sorry).

A Grey Stone, 1963

A Gray Stone (detail)

Martin’s precision creates the illusion of machined perfection, but it’s made by hand, and it has the imperfections of the hand made. The slightly varying lines make the work organic and natural, and the pattern here suggests animal hide, snake skin, human cells. It’s bulk and texture suggests an immense beast, like a rhinoceros or Brontosaurus, while the fine lines reveal the creature’s intricate engineering. Stepping back, we can see the painting’s surface is not uniform, but one that varies slightly across its expanse, like a faint clouding. A Grey Stone is both a work of brute force and exquisite delicacy.

Martin’s paintings can be appreciated for their creativity and subtle beauty in their own right, but it’s in comparison to her abstract expressionist peers that her work really become remarkable. Led by Jackson Pollock –  a Wyoming native who like Martin descended from the high plains – a generation of painters freed paint from the restrictions of line and shape, and reveled in riotous colors and exuberant energy. Martin went in another direction, and her paintings are a study in restraint, calm and discipline. When she experimented with color later in her career, her work goes astray and veers into the merely decorative. (One group of broadly striped painting in pale blue and salmon unfortunately suggests a line of beach towels).

Some of Martin’s most powerful works come when she pared her palette down to minute variations of white. In a collection called The Islands, 12 white-on-white paintings hang together. The grouping invokes comparisons to Mark Rothko’s collection of black-on-black paintings done for the Menil chapel in Houston, and it’s possible that Martin was inspired by them. But despite the obvious similarities, the works have a much different feel: while Rothko’s breathe and pulse with life, Martin’s are cool and distant.

Island VII, 1979

One typical, but outstanding, work in the group is Island VII. A field of white with faint horizontal lines etched in pencil, the painting is sectioned into seven bands of alternating width, and almost imperceptible changes in tone. In some cases, the bands are separated by a single line, in others, two lines in parallel. The closer you look, the more nuanced the work becomes. The white paint clumps, and is thicker in some parts than others. The painting is both uniform, and irregular. And as Martin creates a tension between the detail within the painting and the whole of the painting, she does the same with the single work and the collection of The Islands as a whole. Viewed from afar, they are identical squares of while. Up close, each is distinct.

Not all artists benefit from an exhaustive retrospective, and Martin falls in this group. Unlike some artists, whose work evolves dramatically over time, Martin’s consistency and discipline over the decades means the variations over time are gradual. Seeing them all is overwhelming, and the affect is numbing. Martin, I think, is best hung in isolation, or in a collection of her contemporaries, where her bold and distinct choices are most obvious.