Sean Scully's beautiful abstract paintings at the McIntosh/Drysdale Gallery, 406 Seventh St. NW, are studiously subtle. There is quite a lot going on in them -- they're made up of contrasting, self-contained panels of horizontal or vertical bands -- but the net result is soft, slow and ruminative. In their presence one is stimulated to think not so much of decorative effects as of the time it took to make them, the ways they were put together and the reasons why they were done just so.

For the past decade Scully, born in Ireland 36 years ago, educated in England and now living in New York, has been ruminating in his work about the possibilities of severely reduced, post-Mondrian painting. Not surprisingly, Scully has reached no radical conclusions because there are none left to reach. Instead, he has patiently focused on getting as much of his thinking as possible into the paintings, using no gimmicks, no words, no bold changes in formal approach . . . using, in fact, nothing more dramatic than the old, bare necessity of pigment on canvas.

Thus the relationships in his paintings, between colors, shapes, motifs and surfaces, are perceived to be interdependent: Everything counts. In front of these paintings we are challenged to examine each subtly irregular edge, each muted color, each small sign of underpainting, each mark of the brush, and thereby in some measure are we allowed to experience the concentrated effort of their creation. The exhibition continues through Oct. 31.