The Provincetown Printers were, for the most part, American woodcut artists who left Europe at the outbreak of World War I and colonized Cape Cod. There they developed block-print styles and techniques recognized then and now as comparable to any in the world. And then, somehow, most of the artists faded into such obscurity that in some cases it isn't even known when or where they died.

The inattention that has been showered upon the Provincetown Printers by critics and historians may have something to do with the fact that most of them were women, and passed their productive years long before the NOW generation was born.

But whatever became of the artists, much of their work survives. Its astounding range is handsomely illustrated in a new exhibition at the National Museum of American Art. Assembled by curator Janet Altec Flint, the show is accompanied by a catalogue whose brief biographical notes amount to all that is known about many of these workers in this subtle and demanding medium.

A scant paragraph tells, for instance, what Flint could discover about Juliette S. Nichols, whose "Shoving Off," is perhaps the strongest work in the exhibition:

Born about 1870. Studied art in Paris before arriving in Provincetown in 1915. That year exhibited two works in First Annual Exhibition of Provincetown Art Association. Lived in Marietta, Ohio, and New York City during 1920s. By 1924 had returned to France. Died after 1957.

"Shoving Off," a bold composition in muted colors, brilliantly uses the grain and texture of the wood block to enhance the straining muscles of the fisherman in the foreground, the worn surface of the boulders he's fending off from, and the bellying of the sails in the background. Yet nothing in the composition is strained or compromised to accommodate the pattern of the wood; Nichols simply released the scene she saw there.

The original members of the Provincetown Printers were Ada Gilmore, Mildred McMillen, Ethel Mars and Maud Squire, who went there in the spring of 1915. They had been living and studying in Paris, and Mars and Squire were sufficiently respected in Gertrude Stein's magic circle to be included in The Autobiography of Alice B. Toklas. By summer they were joined in Massachusetts by Nichols and by B.J.O. Nordfeldt, whose development of the single- block color print established the continuing tradition of the "Provincetown Print."

It's a devilishly difficult technique. "First you carve the block," curator Flint said, "then, in effect, you paint a picture on it, and repaint it every time you pull another print. Each print is different, and the possibilities of texture and shading are limited only by your skill and patience."

McMillen, who chose to work only in black-and-white, was unmatched by any of the others in her use of line and shadow, and had such a deft touch that her prints, which seem stark at first glance, go on to suggest as much as they show. She exhibited for several years in Provincetown, then drifted away and died "about 1940."

O brave New World, that has such "unknowns" in't. PROVINCETOWN PRINTERS -- Through January 8 at the National Museum of American Art (Ninth Street exit of Gallery Place station on Metro's Red Line).