"LESSING J. Rosenwald: Tribute to a Collector," which goes on view today at the National Gallery of Art, is a poignant exhibition. To walk among its splendid woodcuts and engravings, lithographs and etchings--all of them assembled by a single great collector--is to sense a portal closing. Lessing Rosenwald, who died at 88 in 1979, was perhaps the last collector of his kind.

By himself he built, and then gave to the gallery, a vast world-class collection, one that dared to survey not just one time or region, but the entire history of Western graphic art. So few fine old master prints remain in private hands that no print collection grand as his could be assembled now.

It begins at the beginning, with a colored Gothic woodcut printed upon linen circa 1400; no older European print has managed to survive. It closes in the present, for Rosenwald collected not just the old masters, but Picasso and Matisse, Herblock, Jasper Johns. In all, he bought the gallery some 22,000 works of art.

There is no way to estimate their current market value. Single small engravings by the German master Schongauer (1450-1491) have fetched prices in excess of $100,000, and Rosenwald owned 80. One etching by Picasso included in his show, the 1935 "Minotauromachy," has sold for $150,000, and Rosenwald owned 139 other graphics by the master. Perhaps half a dozen 15th-century woodcuts may be sold each year; Rosenwald owned hundreds. He bought 263 prints by Albrecht Du rer, 275 by Rembrandt (and nine Rembrandt drawings, too), 153 by William Blake (and 36 Blake drawings), 480 Whistlers and 650 lithographs by Honore' Daumier. But big though his collection is, it is far more remarkable for quality and range than it is for size. For nearly half a century he painstakingly refined it. Rosenwald bought gems.

The show in the East Building is small, and small on purpose. Of the many thousands of objects he acquired, only 100 are on view. Ruth E. Fine, the curator who chose them, worked for years with Rosenwald at Alverthorpe, his semi-private gallery outside Philadelphia. The show that she has given us is a kind of portrait. The 100 works on view include the first and last he purchased, the prints that he loved best and pictures by his friends.

Of course he had advantages. From his parents he received a social conscience, money and a love of art. And his timing was just right.

In 1895, when Lessing was a 4-year-old, Julius Rosenwald, his father, paid $37,500 for a quarter interest in Sears, Roebuck & Co. Soon extremely rich, he was also generous. He built Chicago's Museum of Science and Industry, and started a foundation that gave scholarships to blacks. Augusta, Lessing's mother, who had formed a small collection of the contemporary etchings then so much in fashion, helped turn her son to art. An interest in the beautiful, as well as in technology, were given to him early. He joined the family firm, starting in the stockroom. In 1932, he replaced his father as Sears' chairman of the board, a position he retained until his retirement in 1939.

He began to buy in earnest, to decorate his offices, in 1925 or 1926. "In those days," he remembered, "I knew next to nothing about prints, but still I fell in love. I took to reading European auction catalogues at bedtime--if you stuck a pin in one of them you'd hit a fine example--and I began to buy." At first he sought out etchings of the sort his mother valued. In 1928, he acquired his first Du rer and also his first Rembrandt. "A passion for old master prints took hold immediately," writes Fine. By 1929, he owned 4,300 prints, among them 25 by Cranach, 175 by Du rer, and 200 by Daumier. Rosenwald's collecting paused in 1930. Then, in 1936, as Hitler and the coming war were prying fine art out of Europe, he began to buy again. He was lucky in his dealers, his timing and his friends.

One was Paul J. Sachs, the famous connoisseur, a childhood friend of Rosenwald's, at that time codirector of the Fogg Art Museum, Harvard. It was through Sachs he learned of the existence of more than 300 extremely rare 15th-century woodcuts assembled, in secret, by one Martin Aufha user, a frightened Munich banker. "Mr. Aufha user Jr.," Rosenwald later related, "walked into my office with a package under his arm that looked like something from the delicatessen. I was fearful . . . this was going to be a debacle. The package was unwrapped and . . . I could not believe what I was seeing; there was no such thing. After some time, I finally returned to my usual equanimity. . . . The quality and condition left absolutely nothing to be desired." Rosenwald bought them all.

Sachs introduced him, too, to Elizabeth Mongan, the first curator at Alverthorpe. ("As anyone with reasonable intelligence would, I leaned very heavily on her judgment," Rosenwald wrote later. "If, as I hope, my collection is of fine quality, it is due in large measure to her advice.") When, in 1938, Sachs sold the fine old master prints in his personal collection, it was Rosenwald who bought.

The new gallery at Alverthorpe, with its daylit carrels, its study rooms and print drawers, its walls veneered in elm, was at last completed in 1939. Rosenwald, by then, had formed not one, but two, remarkable collections, one of fine old prints, the other of rare books.

In 1943, he gave them both away. His books and manuscripts were promised to the Library of Congress. He pledged his prints and drawings, those he owned and would yet buy, to the 2-year-old National Gallery of Art.

While alive, he kept his best loved prints around him. He liked nothing more than showing them to others, to teen-agers or children, to housewives or to scholars. Daily he would wander through his deluxe print rooms, a tall and balding man, genial, imperious, part teacher and part host. The drawers would open one by one, the treasures would be offered like presents or surprises. Ruth Fine's little show recalls those guided visits.

It opens with a section devoted to his favorites. Among these are a number of relatively crude, anonymous and heartfelt 15th-century metalcuts and woodcuts from the Aufha user collection. Made as votive images and as souvenirs for pilgrims, most show martyred saints or Bible scenes or other sacred images. Their roughness moved Rosenwald deeply, though he often called such prints "children only a mother could love." Near them hangs a group of far more graceful images by the master E.S. (active 1450-1467), the first engraver known to sign prints with his monogram. His engravings are extremely rare, though Rosenwald owned 14. One, "The Visitation," is the only known impression. Then come three of printmaking's most imposing masters: Du rer, Rembrandt, Blake.

The Du rers include a rare first state of "Melancholia I" (1514), the artist's most mysterious and philosophical engraving, and a superb "St. Eustace." Among the awesome Rembrandts are a small etched landscape, "The Goldweigher's Field" (1651), and a small red chalk self-portrait, circa 1636. Of the Blakes on view, perhaps the most amazing is "Queen Katherine's Dream." A flight of sprites and angels soars through this 1825 watercolor, touched with antique white and gold. The "favorite artists" section of Fine's exhibition closes, quite appropriately, with a group of etchings by Charles Meryon (1821-1868), a highly skilled etcher who died in the madhouse. Rosenwald was deeply fond of his scenes of Paris, and kept three in his dressing room. Those less-than-famous pictures, with their eerie blending of accuracy and oddness, nicely introduces the galleries to come.

The first of these includes a group of images acquired in what Ruth Fine calls "the foundation years," the last years of the '20s when Rosenwald began expanding his collection and sharpening his eye. The first print he acquired, D.Y. Cameron's "Royal Scottish Academy" (1916), is a view of Edinburgh, handsome, but conventional. Also on display is F.S. Haden's 1870 etching, "Breaking Up of the Agamemnon," an early favorite of Rosenwald's, perhaps because it was at that time regarded (a bit preposterously) as "among the great etchings of the world." Near it hangs another purchase from the '20s, an 1889 Whistler etching, a moody view of Amsterdam's slums, canals and women which, unlike the Haden, still appears to be a superb work of art. In 1928, when Rosenwald acquired his first old master prints, his collection began to bloom.

The third section of the show, "The Alverthorpe Years," includes a sampling of images, each nicer than the other. Among the most impressive are a 1480 Schongauer engraving, a Cranach Crucifixion, an 18th-century scherzo by G.B. Tiepolo, a 1925 M.C. Escher woodcut of the second day of Genesis, a superb Degas monotype of ballet dancers lit by footlights, a Karl Schmidt-Rottluff watercolor of irises in flower, and an amazing 16th-century Flemish book whose 275 painted leaves portray, most delightfully, birds and beasts and insects, and one Pedro Gonzalez, a man covered head to toe with long reddish hair. Among the artists represented in this section of the show are Matisse, van Gogh, Jacques Callot, Hogarth, Vuillard, Johns. Also on display are two works that movingly remind us of the man who bought these things. One, "The Whiteness of the Whale," is a 1967 gouache by Philadelphia's Benton Spruance (1904-1967), Rosenwald's "closest artist friend." The other, a 1666 view of London by Wenceslaus Hollar, which Rosenwald acquired in 1978, was the last print that he bought.

"Multiple Images," the last part of the show, may be the most enjoyable. Rosenwald loved pictures--preliminary sketches, early states and proofs--that manage to reveal the artist's mind at work. He owned 47 Rembrandt prints in more than one impression. Here we may compare both the third and fourth states of "The Three Crosses," one of his most impressive--and most impressively changed--images. Two versions of an 1879 Venice scene by Whistler are also on display. Though pulled from the same plate, they are very different pictures: One is dark, one bright with light. The differences derive from the way he wiped the ink from the metal plate. The drawing--plus four different states--of Mary Cassatt's "In the Omnibus" of 1891 could teach a course in printmaking. The other sets of multiple images, by Gauguin, Blake and Du rer, that close the exhibition, are comparably instructive. To compare these images, so close and yet so varied, is to sense again the special joy that was Rosenwald's chief motive, the joy to be derived from the scrutiny of prints. The Rosenwald exhibit closes on May 9.