For the first time since its galleries opened here last April, the National Museum of Women in the Arts has bought itself a painting.

For an institution whose chief mission is focusing attention on neglected women artists, especially those overlooked by other art museums, its initial acquisition -- which cost $22,000 -- could not be more appropriate. The subject is a woman. The painter is a woman. Unlike so many life-size nudes made by male artists, this one carries with it no trace of titillation.

It was painted in Berlin more than half a century ago by Lotte Laserstein, who is now 89 years old. You will not find her name in any standard textbook. She has never shown in America's museums. That her neglect is undeserved is made apparent by the portrait's subtle colors, its locked-in composition and skillful execution. "Traute Washing," 1930, is a distinguished work of art. It went on view yesterday.

Laserstein, who was born in Prussia in 1898, moved to Stockholm during the Nazi era, and has lived there ever since. In England last November, her pictures were displayed in dual exhibitions at a pair of London galleries, Thos. Agnew & Sons Ltd. and the Belgrave Gallery. She had not shown outside of Scandinavia in 50 years. It was at Agnew's that "Traute Washing" was spotted by Washington painter Clarice Smith, a Women's Museum trustee. She reserved it on the spot. At the next board meeting, the purchase funds were raised.

The oil, at first glimpse, seems part modern, part antique. Though its subject calls to mind Venus at her toilette, Susannah and the Elders, or the brothel bathers of Degas, much about the painting suggests a scene from life. Traute's haircut is a haircut of the 1930s. The setting is a garret room washed by soft and grayish northern European light. The props around the figure -- the toothbrush in the water glass, the washcloth on the stool, the tattered bedroom slippers -- are homely, unromanticized. Where Traute grips her sponge, where her hand rests on her thigh, one can almost feel the blood beneath her skin. She is not a goddess or a nymph, but a living human being.

Traute Rose met Laserstein in the 1920s. She was at first the painter's tennis coach, and then her favorite model. Though separated by World War II, they remained friends for 50 years.

Though certain elements of the composition -- the remarkable foreshortening and the cropping of the basin -- might suggest the camera, the painting has about it no trace of that distancing, that chill, of portraits done from photographs. Laserstein has told Caroline Stroude, who helped arrange her London shows, that "Traute, being a natural athlete, was superb at holding long and difficult poses." That sense of slowly built-up friendship and patient observation so apparent in this picture is almost never seen in snapshots. In Laserstein's portrait, as in Lucian Freud's, the sitter seems a person in the room.

In 1919, Laserstein entered the Berlin Academy of Arts, where she spent six years studying with Erich Wolfsfeld, the last two as his Atelier Meisterschu ler, his "star pupil," which entitled her to her studio at the school. Despite the conservative academy's bias against women, she was awarded its gold medal in 1925.

In the early 1920s, in the midst of Germany's runaway inflation, she took a variety of odd jobs -- reducing oriental rug patterns for a carpet manufacturer, decorating china, and, writes Stroude, "illustrating a massive anatomical textbook, which entailed the rather macabre task of drawing cadavers preserved in hydrochloroform."

Her first solo exhibition was held at Fritz Gurlitt's Berlin gallery in 1930. (Gurlitt, Stroude reminds us, was, although a Jew, Hermann Goering's art adviser: "when taxed with this by other Nazis, the Reichsmarshal is said to have replied, "I decide who is Jewish.")

Laserstein herself was one-quarter Jewish. In Berlin in the 1930s, that ended her career. Though three of her portraits were shown at the 1937 World's Fair in Paris, they were banned from the German pavilion. Her mother's Berlin apartment was confiscated by the government, as was the painter's collection of Toulouse-Lautrec's posters. In December 1937, Laserstein left Germany for Sweden. Though her sister Ka te went underground in Germany and managed to survive, their mother was less fortunate. Although not Jewish herself, she was arrested for sheltering Ka te and died in the Ravensbruck concentration camp.

"Traute Washing" is an oil-on-panel 39 inches high. Its colors are subdued. Though, when one looks closely, the thinnish paint seems freely brushed, the picture's composition could not be much tighter. It seems built of roundnesses (her breasts, her knees, the basin and the glass), and of pointed triangles. Look at the way the toothbrush, the skylight, her thigh, her gaze and upper arm all lead the viewer's eye to her pointed elbow, which just touches the left edge of the picture. But your gaze does not rest there. The toothbrush and the washcloth, the slippers and the basin swoop it round again.

The National Museum of Women in the Arts' most recent exhibition, of pre-Columbian jade, had almost nothing to do with women in the arts, and baffled many viewers. Its next, whose subject is perfume, does not seem much more promising. Such missteps have made Clarice Smith's discovery of this Laserstein seem even more important.

Smith knows about art (she has taught painting at George Washington University). She knows about collecting, and about museums, too. (The Smiths have one of the best collections in Washington, and her husband Robert has taken Paul Mellon's seat on the board of trustees of the National Gallery of Art.) The new National Museum of Women in the Arts has had a bit of a rough time. For its many troubled champions, the Laserstein acquisition should help shaken hopes revive.