"In Pursuit of. . .," the National Museum of American Art's display of etchings, lithographs and engravings spanning some four centuries of printmaking, is a potpourri in pursuit of a theme. But once you grasp that the title is a harmless gimmick, you can savor the show as a generous grab-bag.

Assembled from the private collections of Washington Print Club members, the 61 prints range in style from Flemish artist Lucas van Leyden's delicately wrought 1529 engraving, "The Expulsion of Adam and Eve," to American Roy Lichtenstein's hard- edged and Bendayed 1970 lithograph/silkscreen, "Peace Through Chemistry I."

In between there are such stylized works as Claire Leighton's 1932 wood engraving, "Bread Line," its subject looking more like Art Deco ornamentation than people, and "Ark V," Arthur Geisert's whimsical 1980 hand-colored etching in four plates.

The point of the exhibition is to reveal the medium's impressive versatility. There is, for instance, Fritz Eichenberg's 1935-36 wood engraving, "The Gay Nineties," a satirical scene of ladies and gentlemen in evening dress ensconced among palm fronds in a bistro. With clear-cut lines and stark blacks and whites, the effect is cartoony.

How different from Thomas Hart Benton's 1942 lithograph, "The Race," a dreamy depiction of horse and locomotive with the looks of a Di Chirico painting. Everything about the work -- the ground, the sky, the steam trailing from the train -- gives a sense of enormous speed; the effect is surreal.

There are some special treats included, among them: Henri de Toulouse-Lautrec's 1896 color lithograph, "Debauche," in the French master's distinctive style of airy elegance; and William Blake's 1810 engraving, "The Canterbury Pilgrims" -- this one, for those who need reminding that the English fantasist was almost as good a visual artist as a poet.