SHORTLY AFTER he became curator of prints and graphics at the National Gallery of Art, Andrew Robison asked himself a question:

Why should his Gallery, he wondered, so often seek abroad what it might find at home?

The admirable display of Italian master drawings that goes on view today in the Gallery's West Building is the first fruit of his musings. Foreign institutions -- in Peking, Dresden, Leningrad, Cairo, and Madrid -- often have sent loan shows to Robison's museum. But this one comes from Illinois.

"Italian Drawings in the Art Institute of Chicago," which celebrates a colleague, Chicago's Harold Joachim, and the careful acquisitions of a sister institution, deserves to be the first of many such exhibits. Robison is right: If the Gallery is willing to arrange exchanges with the Hermitage, the Prado or the Louvre, why should it not do likewise with the Boston or the Met? There is in America, as this show reminds us, not one art museum whose exhibition program would not be much enhanced by well-selected loan shows borrowed from the rest.

The Art Institute's exhibit is in part a survey of old Italian art, and in part a series of exquisite one-man shows -- by Tiepolo, Piazzetta, Guercino, Castiglione, Parmigianino, Taddeo Zuccaro and other well-known masters. Chicago owns no Michelangelos, no Raphaels or Leonardos. But despite the absence of that great triumvirate of the high Italian Rennaissance, its collection is among the finest in the land.

"In America," says Robison, "in the field of Italian drawings, three other institutions -- the Metropolitan, the Fogg and the Pierpont Morgan Library -- are way in front of all the others. fBut, thanks in part to Joachim, Chicago now, it seems to me, is leading the next rank."

Joachim is a connoisseur.He rarely writes or teaches. His reputation is instead based upon the brilliantly selected, mutually supporting objects that his fine museum has decided to collect. He does not have a one-track mind, nor does he only seek out those pictures that were made by art history's acknowledged stars. There are thousands of Italian drawings, many of them second-rate and rarely shown in the Art Institute's collection. It was Joachim who picked the 151 that are here on view.

The selection at the Gallery includes works both large and small, preliminary sketches as well as finished drawings, architectural studies, landscapes, portraits, fantasies. It seems, at least at first, the sort of show one should enjoy a picture at a time. But so great is its variety, so wide is its range, that is seems in retrospect greater than its parts.

Among its many high points are:

A charming Tuscan landscape by Fra Bartolommeo (1472-1517), who, after 1506, when Leonardo, Raphael and Michelangelo went to rome from Florence, was perhaps the finest painter left behind. What makes this work so pleasing, as the catalogue observes, is that it "seems to have been drawn from nature, apparently for the artist's own pleasure."

A set of eight superb works by the Venetian master Giambattista Tiepolo (1696-1770), pictures that together survey more than 40 years of his illustrious career. He draws with such assurance, and applies his colored washes with such masterful control, that even when he sketches at great speed, his figures sit there solidly in revealing sun-bright light.

Nine highly polished portraits by Giovanni Battista Piazzetta (1682-1754), all of which were owned once by Field Marshall Count Johann Matthias von der Schulenberg, a Hapsburg officer (and a patron of the artist) who, in 1718, "after several ferocius campaigns against incredible odds" led the Venetian forces as they repulsed the Turks.

Four extraordinary sheets by Giovanni Benedetto Castiglione (1609-65), which include informal studies of birds and dogs and cows, and one highly finished monumental work, "A Pagan Sacrifice," done with colored oil paints.

A pair of spooky pictures by Alessandro Magnasco (1667-1749), whose ambiguous spaces and nervous lines and shadows predict those later seen in the works of Piranesi. These are two of the finest Magnasco drawings that have managed to survive.

A "Sheet of Studies for the Blinding of Elymas, Sacrifice at Lystra, and a Holy Family" by Taddeo Zuccaro (1529-66), whose many figures drawn in as many styles present us with a catalogue of the artist's thoughts.

A set of four fine drawings by Guercino (1591-1666) in all of which we feel as if the artist's pen is dancing, so musical and liquid are his freely moving lines.

Few of us today can grasp how miraculous it must have seemed, in the days before photography, to see an artist's moving pen conjure upon paper the look of real life. The thrill that once existed in the act of drawing crackles through this show.

The Art Institute is publishing four selective catalogues covering the finest drawings that it owns. Italian Drawings in the Art Institute of Chicago" by Joachim and his assistant, Suzanne Folds McCullagh, the first volume in the series, is the admirable catalogue that accompanies this show. The book, writes Harvard's Sydney J. Freedberg rightly, "conforms to the best standards for the writing of a catalogue in this field. The level of expertise is very high, the research thorough and precise, and the style of writing in the catalogue entries is lucid and comprehensible." It is also fully illustrated.

The patient viewer, seeking more information than that found on museum labels, might take a copy with him as he wanders through the show, which will be on view here through March 2.