The Geneva-born, 18th-century artist Jean-Étienne Liotard (1702-89) was a quirky character for a quirky time. Having spent four years in Constantinople (1738-42), he dressed like a Turk in robes and a red cap and sported a long beard, a very non-European attribute. Orientalism, a fad of the times, became part and parcel in his life and work.

Called "the Turkish painter," Liotard garnered a certain amount of attention in Europe, which he parlayed with his skill as an artist, chiefly in pastel, to become a portraitist to royalty and the merely rich in half a dozen countries. A Protestant at a time when France was resolutely Catholic, he failed to become a member of the French Royal Academy, one sure route to earning a living as an artist. So he really needed another way to promote himself -- and he found it.

Liotard with a Beard from 1749, one of the artist’s many self-portraits, greets visitors to "Jean-Etienne Liotard (1702-1789): Swiss Master," currently on view at the Frick Collection. This revelatory and pleasurable exhibition is not a retrospective but does serve as broad introduction to the artist, his first monographic show in the United States. Almost all the works, except one owned by the Frick, are being shown here for the first time.

The exhibition is filled with wonderful faces -- some exotic, some famous and some intimate. Many of Liotard’s best works are portraits of himself and members of his family. Liotard is set apart from the other more academic French School pastel portraitists of the period like Jean-Baptiste Perronneau, Jean-Marc Nattier and Quentin de la Tour by his realism, the depth of his psychological probing and the beauty of his touch.

Liotard’s delicate sense of color and shading produced creamy skin tones, flesh that is both gorgeous and strikingly individual. Liotard’s training as a miniaturist and enameller provided him with his basic technical tools. He perfected them over time, experimenting with many different kinds of marks in various layers that he put to good use in accurately describing position and personality.

Liotard’s chalk and watercolor of his wife and eldest son from 1766 shows how ruthlessly honest he could be at a time when flattering portraits were the norm. His wife’s parted lips are dry, her expression one of fatigue, while her sprightly and beautiful child seems a little bashful.

The woman’s gown and coif are fashionable. We know she has the money to dress well, but the moment captured underlines her social status less than her being part of a fading older generation that her already somewhat distant, forward-facing son will soon be bold enough to replace.

Liotard is every bit as hard on himself. Liotard Laughing (ca. 1770) pictures the approximately 68-year-old artist before a drapery. It’s an in-joke. The painting refers to a legendary contest in ancient Greece between the artists Zeuxis and Parrhasius. Zeuxis painted grapes so realistically that birds swooped down to eat them. He then asked Parrhasius to draw back the curtain to reveal his painting. But the curtain was not real but painted by Parrhasius, whose skill could fool not only birds but his fellow artists.

In Liotard Laughing, the artist shows himself aged, with a missing tooth, wearing his startling Turkish cap, having the last laugh on the art establishment with another one of his truthful pictures. Liotard’s exuberance in the face of advancing age is remarkable.

Though Liotard eventually shaved his beard as a present to his much younger wife, after her death he grew it back. A graphite and chalk self-portrait from 1782 shows the now-bearded artist at work on a drawing. Instead of employing his usual three-quarter pose, Liotard is shown full-length and seated in a chair, surrounded by empty space, which echoes his loneliness.

Liotard was especially perceptive about children and not just his own. One highlight of this remarkable show is the group of 11 pastels of children of Archduchess Maria Teresa of Austria -- including Marie Antoinette, soon to become wife to Louis XVI -- made for the queen herself. The portraits are executed in a combination of media using a variety of techniques. These insightful images so pleased Maria Teresa that she took them with her whenever she traveled.

Each face glows with a seemingly inner light. One technical innovation that Liotard employed was to heighten the color on the back of the drawings. The added intensity gives each sitter a greater three-dimensionality. The children become almost eerily present.

If one compares Archduchess Maria Karolina of Austria (1762) with her sister Archduchess Marie-Antoinette of Austria (1762), one can sense quite easily the different personalities of the two. Maria Karolina, calm and resolute at only age 10, became the wife of Ferdinand IV, king of Naples and the Two Sicilies when another of her sisters died before she could marry him. Maria Karolina was a more determined monarch than her negligent spouse, meanwhile bearing 17 children.

Her sister, Marie Antoinette, is pictured at her sewing, erect and imperious, protective of her own thoughts and desires. After becoming queen of France, not even her mother’s letters could coax her from her headstrong and, eventually, head-losing ways. Before the guillotine could claim her in 1793, the artist who so beautifully expressed her willfulness would be dead for four years.

Because there are so few of Liotard’s works in public collections, the Frick exhibition is a great opportunity to study his subjects and style. The Frick borrowed pieces from Geneva’s Musées d’Art et d’Histoire in the artist’s native Switzerland, which contains more of Liotard’s work than any other public museum, adding its own single Liotard, and several works from private Swiss collections. Only Liotard’s prints and late fruit-and-flower still lives are missing from this wonderful introduction to his oeuvre.

In this country, the J. Paul Getty Museum holds five Liotard works, the greatest number in the U.S., among them the masterpiece Still Life: Tea Set from around 1781-83. The Cleveland Museum of Art has one portrait. If any one knows of more, I’d like to learn of them and so would Renée Loche and Marcel Roethlisberger, who are compiling a Liotard catalogue raisonné.

Kudos to the Frick Collection and especially to Frick chief curator Colin B. Bailey, who with the assistance of Kristel Smentek, Andrew W. Mellon curatorial fellow, organized "Jean-Etienne Liotard, (1702-1789): Swiss Master."

N.F. KARLINS is a New York art historian and critic.