ROBERT MARX has never worked in the mainstream. He found his expressive forms long ago -- elongated, emaciated figures with anguished faces -- and he has used them ever since to play out the human dramas, foibles and tragedies that preoccupy his art.

Little has changed in his current show at Bader Gallery, but his work has never been better.

Known chiefly through his etchings, Marx -- professor of art at the State University of New York, Brockport -- is here represented by sculpture, drawings and several large paintings, all masterfully rendered. The subjects are characteristic: an antiwar piece titled "Hero's Widow" -- a broken woman left alone with her husband's war medal; "Patient," one of several works dealing with the imprisonment of the ill; and "Cleric," an irreverent jab at the powers that be.

Illness has played a heavy role in the artist's life in recent years, and the figure of a dying woman often reappears, most powerfully in a bronze titled "Woman at Rest." Rendered in the horizontal format of a sarcophagus, the collapsed body is enveloped with forbodings of death, though we know it to be alive by the pained eyes and moving fingers.

It all sounds depressing, but so life can be, and few artists care to deal with such matters. Marx's attraction to those often forgotten can be seen in some of his most intimate and beautiful productions -- his drawings and limited-edition books. One such book, titled "Old Women" (ed. 25), includes etchings and poems by Frantisek Italas; another, "Crime Trial" (ed. 100), was produced in collaboration with the radical Catholic priest Daniel Berrigan, who wrote the spellbinding text. Neither should be missed.

One could quibble that Marx is a mannerist, using repetitious forms. But the work is too poignant to ignore. The show continues at 2001 I St. NW through Saturday. Hours are 10 to 6. Syd Solomon's Abstracts

Syd Solomon splits his time between Florida and East Hampton, N.Y. -- the art colony where the de Koonings, Lee Krasner and other famed Abstract Expressionists hang out. It is therefore no surprise that he makes Abstract Expressionist paintings with sunny landscape overtones.

What is surprising, however, is that the work, now on view at Phoenix II, is so slick and superficial, given the artist's talent with a brush. Half of these paintings look dashed off -- some drip and splatter here, a gestural smear there. While the color can be pleasing, it can also be apallingly garish: "Coastcall" looks tailor-made for a bordello lobby.

Other works like "Sagg Sentinel" and "Summer Module" seem to have had more thought put into them, with the result that they have greater dignity and control. Could it be that sunshine and thinking don't mix? The show, at 1875 I St. NW, continues through Nov. 6, and hours are Tuesdays through Fridays, 11 to 6, Monday and Saturday, 11 to 4. Jill Romanoke's Baskets

The art gallery at Glen Echo Park is always worth a visit, and the current show of baskets by Jill Romanoke and silver jewelry by Susan Tamulevich is no exception. Both artists teach at the Park -- one of the city's great creative art resources, now threatened by escalating budget cuts.

I went especially to see Romanoke's sculptural, highly inventive free-form baskets made from unstripped twigs and vines, but found that she had turned traditional, and is showing only straightforward basket forms made from willow. They are handsome, but far less interesting than her other work.

Most intriguing are some sculptural necklaces Romanoke has fashioned from brass, grass and colored thread. The show continues through Nov. 2, and hours are Mondays through Fridays, 10 to 5, Saturdays and Sundays noon to 5.