It's sad how quickly some artists - even very good ones - drop from sight. And even sadder how few of them ever get a second chance. When one does, it's usually for the wrong reason: The artist's heirs want to empty their attic of his paintings, or a gallery decides to stir up interest in pictures of his they haven't been able to sell. In either case, an exhibition is mounted, the public is informed that a major figure has been ''rediscovered,'' and some art-world interest is created. Unfortunately, that interest is often limited to a few old friends of the artist, a critic who leaves immediately, and perhaps a dozen collectors who can't quite make up their minds to buy.
There are times, however, when renewed interest in a neglected artist results from a museum's inclusion of several of his paintings or prints in a major exhibition, or from an influential gallery's decision to hold an important retrospective of his life's work.
That may still not do the trick, but it is at least a step in the right direction - especially if the quality of the work is high and the show is intelligently assembled.
The print retrospective of James E. Allen (1894-1964), now at the Mary Ryan Gallery here, fulfills both qualifications. The lithographs and etchings on view include some of the best graphic images produced in the United States between 1925 and 1945, and their selection - with only four or five prints out of his total production missing - is remarkably complete.
That Allen was among the best American printmakers of his day will come as a surprise to almost everyone except a few print professionals, and even some of these will have to admit that they hadn't known of him until his inclusion in the Metropolitan Museum's ''Working America'' show last year. This ignorance is all the more unusual since he was very well known during the 1930s and '40s, with many awards and commissions to his credit. True enough, he represented the kind of traditional printmaking that became thoroughly unfashionable - thanks to the influence of S. W. Hayter and Mauricio Lasansky - around 1950. But Howard Cook, Martin Lewis, Louis Lozowick, and a few other printmakers survived, and their work was roughly of the same quality as Allen's.
Whatever the reason he faded from public view, the important thing is that his etchings and lithographs are once again in evidence - and are very good.
By and large, Allen's prints depict the channeling of human resources toward industrial goals, focusing on the various kinds of labor needed to create our modern world. The men in his pictures work hard to build bridges, construct skyscrapers, and dig tunnels, but his attitude toward them is far from romantic or sentimental. A laborer may possess dignity and deserve respect, but for Allen , backbreaking work is hardly the pinnacle of human aspiration. His subjects do what they must, but they don't glory in it. Nor are they slaves of a capitalist system, as was depicted in quite a few prints of the '30s.
Allen's graphic images are compactly designed, forcefully but ''accurately'' drawn, and shrewdly orchestrated for maximum black-and-white effect. They are monumental in conception and precise in detail, and they're as effective at 10 feet as when held in the hand.
That should come as no surprise, considering how carefully he went about his craft. He was disciplined and hardworking, first as a student in Chicago and New York, then as a professional. He learned etching from Joseph Pennell and William Auerbach-Levy, sharpened his perception of three-dimensional form by doing sculpture, and in general made certain that everything he did was thoroughly grounded in observation, knowledge, and experience. Never satisfied with halfway measures, Allen executed exhaustive charcoal studies for all his prints, and he spent close to 10 years experimenting with copper and acid before allowing his etching to be exhibited.
Such care soon began to pay off. In 1932 he won two major awards for his etching ''The Builders,'' and in 1933 he was honored for his ''Brazilian Builders.'' He continued to exhibit and to receive important prizes for his graphic work until the late 1940s, when he decided not only to give up printmaking for painting, but also to shift to a more abstract mode, under the guidance of painter and teacher Hans Hoffmann. None of Allen's paintings have ever been seen by the public, but one would have to assume, given his talent and dedication, that they turned out quite well.
Viewing this show at the Mary Ryan Gallery is highly rewarding for anyone who loves dramatic, crisply black-and-white images - and humbling for those who thought they knew everything about his period but had never seen his work. Allen's impressive lithographs and etchings are a reminder of how badly we treat our artists once fashions in art change, and a hint that other excellent printmakers may be awaiting rediscovery.
Here is a choice opportunity to study a large group of highly representative graphic works of the prewar era - works that pinpoint much of what was best in American printmaking at that time and are remarkably free of the weaknesses and excesses that cause the prints of several of Allen's contemporaries to seem dated and provincial.
We need more shows like this. We've become much too willing to dismiss the graphic work made by American etchers, engravers, lithographers, etc., before the days of Hayter and Lasansky, and to assume that the large, multicolored, technically innovative, and frequently decorative prints that have flooded the art market since the early '50s are the only prints of quality this country has produced.
We couldn't be more wrong! Much of what was etched or engraved in this country between 1900 and 1950 was bad or mediocre, but that is true of all art, regardless of time or place. The master printmakers, on the other hand, were very good, and occasionally were very close to first-rate. Figures such as Pennell, Sloan, Bellows, Lewis, Hopper, Arms, Wood, Landeck, Wengenroth, and at least a dozen others deserve all the respect they can get. And it's obvious from this exhibition that the name of James E. Allen belongs on that list.
At the Mary Ryan Gallery, 452 Columbus Avenue, through Sept. 16.