"Nathan Oliveira: A Survey of Monotypes, 1973-1978" is the finest exhibition that the Phillips Collection has mounted in some time. Nathan Oliveira searches as he teaches. To wander through his show is to set out on a journey through a long-neglected medium and an artist's mind.

It is the monotype that launched him. Half printmaker, half painter, the monotypist paints with inks or oils on either glass and zinc, and then presses paper against the still-wet plate. Degas, that graceful, flawless Frenchman, that master of the monotype, was Oliveira's initial inspiration. By studying Degas, and the moving on to Goya, and, after Goya, Rembrandt, the California painter set out on the voyage that would liberate his art.

He takes his viewers with him. His exhibition opens with formal variations on a theme by Goya. Beginning with an image from a bullfight print of Goya's he dissects it and transforms it, reduces it, abstracts it, producing as he does so pictures that would justify a visit to his show.

But they are just the start. Oliveira next begins an exploration of a Rembrandt etching, the one called "The Three Crosses." his Rembrandt transformations are less formal than thematic. From the master's mourning figures bowing at th cross he unexpectedly extracts a bound and bundled image, half package and half corpse.

Colors, colored fogs, shamanistic faces, weapons, birds and coiled lines gradually begin appearing in his art. The sources of his images -- Old Masters and oil memories, pre-Columbian and Indian art -- once mined are abandoned. Yet as they go they leave behind spells, strange incantations, that summons up the guides that lead the artist through his art.

There is something mild about Oliveira's monotypes. Their figures occasionally seem awkward, their colors rarely dazzle, but the pictures on display, linked to one another, glow with rare intelligence. The Baxter Art Gallery of the California Institute of Technology organized the exhibition. Lorenz Eitner wrote the first-rate essay in the catalogue. The Oliveira exhibition closes feb 17.

"Images of the '70s: Nine Washington Artists." Carl Lists's show at the Corcoran has spum off half-a dozen local exhibitions. Manon Cleary's "hand" paintings are on view at Osuna's, there are drawings by Jennie Lea Knight (more admirable than her Corcoran works) displayed at Diane Brown's, and works by Michael Clark and Kevin MacDonald are simultaneously on view at Harry Lunn's in Georgetown. All these exhibitions will be up for a while, but this afternoon is the last opportunity to see "The Laundry Show: Images of January 1980: Fifteen Washington Artists" at 1735 Columbia Road NW.

A warm and welcome throwback to the friendly exhibitions that Bob Stark and Lucy Clark once gave to their colleagues (and to the rest of us as well), "The Laundry Show" is a footnote full of fun. It was organized by artists. Its budget was $75. Every time the artists of this city mount such an exhibition one wonders why they don't do it more often.Leslie Kuter's dying Vincent van Gogh, Bill Lombardo's airplanes, Sworoff's tattooed ostrich, Appel's teeny Seascapes, and Tom Green's hungry bird are among its nicest works of art. They'll remain on view until 6 p.m.

"Paintings of the Holocaust," Mindy Weisel's exhibition at Jack Rasmusens's 313 G. St. NW, is a show in which a poignant beauty blossoms out of pain. Weisel is a young abstract expressionist whose dark pictures somehow manage to appear not at all old-fashioned. They convince one of her passion. Feelings boil in them. Glints of Blue, of light, of hope, twinkle in their seas of superimposed blackness. Occasionally they seem too elegant, too pretty, for the horror and the grief that they nonetheless manage to express. Weisel is a young Washingtonian worth watching. Her exhibition closes Feb. 2.

Olivetti, a company that has few peers when it comes to getting advertising mileage out of Good Design, has somehow talked the government in exhibiting a corporate ad in the Pension Building on G Street NW. One wonders how a film that has employed designers as accomplished as Le Corbusier, Louis Kahn, Kenzo Tange, James Stirling and Richard Meier managed to set up an exhibit as confusing as this one. The arrows on it's cardboard panels lead the viewer nowhere. Any first-year architectural student should be able to come up with a more legible display. Olivetti's showrooms, calculators, factories and posters should no doubt be applauded for their chic, but this over-large labyrinth of an exhibit instead brought to mind the portable Olivetti typewriter I battled while in college, that tinny, light machine whose ribbon often tangled, whose keys so often stuck.