Vladimir Kagan is very much like his furniture, sophisticated but friendly, elegant but easy. Unlike Bauhaus furniture, Kagan's is so comforable his clients sit in the living room even when there's no company.

Though Kagan is only 52, it sometimes seems as though he's been designing furniture for half a century. He hasn't really, though he started in his father's furniture workshop as a teen-ager.

Looking back over his work, it's impressive to see how often Kagan's designs were 10 years ahead of his time. So it isn't surprising that Marty Bronson, director fo the galleries at the Fashion Institute of Technology here, has seen fit to organize a retrospective show of Kagan designs, continuing through June 28 at 7th Avenue at 27th Street.

Unlike many modern masters, the eight new designs shown here for the first time are even better than the 30-odd-year-old pieces that initially made his reputation, though the rare woods and the fine cabinetry become rarer as time goes on.

The leitmotif of Kagan's designs has been his love of sumptous, costly material and fine craftsmanship.

Kagan, like his father before him, his first a sculptor. (His father, Illi, designed and made furniture in the modern manner in Czarist Russia and later in Germany. After he retired, Illi Kagan worked as a sculptor into his 90's. Some of his beautifully sculptured wood figures stand in Kagan's Fifth Avenue apartment.) Vladimir Kagan's sculptured walnut rocking chair of 1955, covered with crewel embroidery by Erica Wison (his wife), is the prime example. The shortage of fine wood-craftmen has cut down on the number of such pieces he can make now, but the 1976 matrix bar stool still continues the tradition.

Kagan was one of the first, if not the first, in our time to remember that sculptured furniture could be soft sculptured -- overstuffed upholstered furniture with the detailing in the uypholstery instead of in the cabinetry. These soft, squashy sofas and chairs make you feel cuddled, caressed, as if you were sitting in a lover's lap.

Soft-sculptured furniture is not really a departure for Kagan, because the whole hard edge period, his work always has been curvillinear, soft edged, romantic rather than classic. In 1975, he designed what may be the greatest piece of furniture of the decade -- the Deco Chaise, a channeled upholstered chaise. Like most of his furniture, the chaise is witty -- it looks exactly like a tongue sticking out at you. The appearance of cantilever is however, deceiving. As with most of his furniture of the period, the support is an almost invisible Lucite piece.

Kagan's Omnibus sofa grouiping of 1970 probably qualifies as the most ripped off design. The sofa was the first to have multi-levels, so you could perch, sprawl, lean, or recline at several levels. Kagan is still bitter about the great success of the cheaper copies from which he derives no royalties.

The new seating designs in the show are an extension of the Deco Chaise, and the Omnibus sofa. The Nouveau Deco Chair has a wonderful rolled back in a series of cylinders. The Wing Chair is just as comfortable as the classic Sheltered Chair from which it derives.

Of the eight 1980 designs, completed just in time for this show, the best is undoubtably the Landscape Bedroom. The single piece has everything you need to furnish a sybaritic bedroom. Moreover, the unit is designed to "float" in the room, an enormous help because few walls can accomodate a king-sized bed anyway. The back of the bed is a long cabinet with drawers not only for clothes, but also sections that pull out to be a desk and a makeup talbe. On the other side, the headborad is in soft rools like the Nouveau Deco Chair. Lighting and night tables are, of course, built in. And the footboard is another rolling cylinder. The super bed resembles nothing so much as a dream barque from "Tales of Hoffman."

Kagan says the bedroom hasn't been priced yet but will be somewhere around $12,000.

His woman's executive desk is another multi-use piece of furniture with a mirror, telephone, clock and speaker built into its lacquered, stainless steel and leather form. Its price is about $13,000.

In some cases, for instance the 1956 roll-top desk of bronze and teak wood, the old pieces have been revised for today's production. Instead of a metal base, the roll top desk of 1980 has a lucite base. The effect isn't as good, but it still effective in a different way.

The New York show came about because an antique collector bought a house from an estate. Kagan had designed all the furniture in the house. The antique collector called him up and asked if Kagan could re-sell the furniture. Instead, Kagan bought it himself, and the idea for the show was born. A few of the pieces, including a set of rather unfortunate wire patio furniture (not nearly so successful as Harry Bertola's diamond chairs for Knoll), came from the Kagan's Nantucket cottage, and the delightful rocking chair came from their New York apartment.

The question now is what will happen to the collection after the show is over. The Renwick Gallery would seem an obvious place to show it. And why not a Smithsonian Traveling Exhibition Service Tour? The handsome platforms and dividers for the show, all covered in costly fabric suede, are designed to fold up as containers. The splendid installation is colored in deep purples and dark reds set against a cream color.

Kagan's furniture is beautiful, but beauty, like everything else these days, costs astronomical prices. Kagan's furniture is made in a small workshop in Long Island City (he bicycled there from his Fifth Avenue apartment during the transit strike) by 65 experienced craftsmen. His pieces are rarities and occassionally works of art. This exclusivity adds, of course, to their desirability.

But it's a shame that a good, high-quality manufacturer doesn't buy some of Kagan designs and mass produce them so we could all have a dream barque in our bedrooms. Maybe that's the idea for Kagan's next half century.