NEW YORK -- Raisa Gorbachev's designer hates short skirts.

The last time hems were high, in the '60s, said Viyacheslav Zaitsev, "women got divorced because of the miniskirt. Everything was exposed ... There was no mystery left."

And mystery, to the Soviet Union's best-known couturier, is much of what fashion is all about. This may be the era of "openness" in Soviet politics, but in Soviet fashion, as with much else in Russian life, covering up is still the rule.

It even extends to sex.

"You have to have the woman concealed in fashion," Zaitsev said this week during his first New York visit. "You have to have a halo of mystery so man doesn't know everything and would be more excited ... The more you can learn about the woman, discovering many layers that conceal her, the more interesting she is."

This makes him, he suggested, something of a marriage therapist as well as a dressmaker. Zaitsev remembers a woman from Siberia who came to see him in his Moscow fashion house. She was married with three children and had read about him in the press.

"I feel my husband is losing interest in me. He doesn't like something in me," he says she confided. "Please try to help me solve this problem and have him come back to me. Tell me how I should look."

He remembers the day another woman pleaded, "I must stop the man I love from leaving me. All I have is one day and one night. What shall I do to keep him from leaving me?" Zaitsev clasps his hands and opens his eyes wide. "I had to resolve the problem of what she was all about and also to choose something that could be sewn by her in a matter of hours."

Two days later she returned with a bouquet of flowers for him. The man had not left. "It was VUNDERFOLL!" he says in the few words of English he has learned since coming to New York two weeks ago. "I was so HOPPY."

Zaitsev describes his clothes as "modestly seductive," but they appeared out of sync with the lean and short mood of popular design elsewhere, and they met a less than enthusiastic reception here Tuesday from about 300 buyers and press plus at least a dozen Russians at the Starlight Roof of the Waldorf Astoria. He used top New York models, the best show producer, music director, hair designer and lighting professional, and achieved a personal success regardless of the skepticism toward his clothes.

"He is a tremendous talent. He understands cut and seaming and a woman's body," said Associated Merchandising Vice President Bernie Ozer. "I can see Politburo wives fighting over the clothes."

Others had trouble imagining American women in the designs, which are cut with ease and roominess and have considerable length and often many layers. His strong points are his dramatic coats and some body-conscious black dresses that were in the spirit of Mainbocher. "Someone needed to tell him that for the American market the clothes need fewer bows, fewer layers and shorter hems," said one New York retail executive who asked not to be named.

If Zaitsev's layered look springs in part from Russian winters, it also appears a direct outgrowth of his philosophy of fashion.

A woman is like a book with many pages, he says. "She should have all these pages, and with each page a man should discover something new. You can read that book all your life. But when a woman is just a front and back cover without any contents, well, man will look for another book -- another woman."

Actress Colleen Dewhurst had no trouble spotting things she would like to own, particularly the charcoal-gray coats, the easy paisley silk costumes edged in shiny cire', and the black and white print dresses. And she loved the exuberance of Zaitsev, who danced down the runway at the end of the show, arms extended, twirling joyously in his emerald green silk jacket and black silk pants. "To look at him on the runway with all his openness -- you know why you love the Russians," she said.

Some of Zaitsev's clothes shown here are from his fall collection now on sale in Moscow; others are for spring, designed in Moscow but licensed to be made in North Carolina for sale in the United States. This joint venture, boosted by perestroika, the new Soviet policy that permits Soviet trade groups to bargain directly with the West, was initiated by Intertorg, an American trading company that more typically deals in heavy equipment like tunneling machines.

Fabrics for his American collection will be American or European, but in Moscow he uses Soviet wools and silks. "And we have a tremendous heritage of costumes ... a bottomless pit. There are so many ideas, we don't need to look elsewhere. We have our own riches." He doesn't tap directly into the vast ethnic heritage of the Soviet republics for ideas for his clothes. "I don't have to use it to design my collection. I studied the culture seriously when I was young and this culture is a part of me -- it seeped into me long ago."

Rather than looking back, he is trying to discover a new way with clothes. "I'm trying to find a new esthetic for the future of costume. I think we in our generation are responsible for what we leave to the next generation. We speak of the 17th, 18th and 19th centuries, but what are we leaving from the 20th century? In my fashion I am beginning to establish the esthetics of the future."

This was Zaitsev's first visit to the United States, and he came by way of Munich and Du sseldorf, where week-long fashion events were being held. "It gave me a measure of understanding of the high level of fashion in the West." But New York is different, he says. "People are dressed with more variety in New York. There is no one general style."

In his two weeks here, Zaitsev has met with his idol, Bill Blass, and praised Oscar de la Renta, saying, "I am experiencing a very healthy envy." Both designers took Zaitsev on tours of their workrooms and explained every aspect of their businesses. Several evenings he went dancing with the fashion crowd at the Tunnel and the Palladium.

But it is all so much easier here than in the Soviet Union, he says. "In Russia in the past 25 years I always have problems getting the right fabric, the right colors, the right accessories. In New York, a designer has an easy job. Everything is accessible."

Zaitsev is divorced and has two sons -- Egor, a designer for the avant-garde in Moscow, and Dimitri Vlasinkov, a photographer, who is married to an American and lives in Atlanta. The designer himself was born in Ivanovo, a small textile industry town about 225 miles from Moscow. His father was a laborer and his mother a cleaning lady and laundress.

When he graduated from technical school in 1956 at 18, his mother bought him his first suit -- corduroy, he remembers. As a talented student, he was sent for additional studies to Moscow and six years later graduated from the Moscow Textile Institute to a job designing garments for farmers and industrial workers.

In 1965 he began working for the largest fashion house in the U.S.S.R., the Moscow House of Fashion, designing clothes for large-scale production. Finally in 1978, after 13 years of frustration designing clothes judged too radical to be produced, he began working, at the age of 40, in a salon. For the last five years he has headed Zaitsev's House of Fashion.

There are three fashion shows weekly at his place, always a sellout at 3 rubles (about $5 a ticket), where women can select patterns plus a selection of clothes in a limited size range -- mostly Sizes 10 or 12. Zaitsev will also make up something in a customer's own fabric. He also has a catalogue from which customers can choose.

"My house is open for all, for whoever likes my styles," says Zaitsev. Even though some things may cost $300 -- an average monthly salary -- Zaitsev denies that makes them expensive. "That's a primitive approach," he says. "My fashion is not expensive compared with American designers," he adds, naming Blass, de la Renta and Calvin Klein as the designers he admires nost. "My clothes cost one tenth of what they would cost in the West."

His own salary -- 300 rubles, or about $400 a month -- is a small percentage of what his American millionaire counterparts are paid, but he says he doesn't mind. "I am on a salary. I can make four samples or 100 and I will still get $400 a month." He doesn't know if he will be paid extra for the American venture. "We are not accustomed to thinking that way. I love my profession. If I want to earn extra money I have possibilities, including lectures or making clothes for actresses, ice skaters and singers," he says. Of more concern than money, he says, are his hopes for more modern equipment for his fashion house.

Never would he suggest to Raisa Gorbachev -- or any other client, for that matter -- that she wear a miniskirt, a style he considers, well, positively undemocratic. "That makes fashion very exclusive. Most women cannot afford to wear short skirts because they don't look good in them," he says. The short cocktail dresses in his New York show were meant as a spoof of the style.

He remembers the last go-round in short skirts. "It had a very bad psychological effect," he said. "It gave women an inferiority complex."

Zaitsev considers his clothes quite similar in spirit to Blass' and others'. "We all like clothes that are comfortable and feel liberated, yet allow the woman to be charming and attractive ... Of course your sophistication is much higher. Your level of civilization, as far as fashion is concerned, is incredibly high, and we are just beginning a renaissance now."

He knows several French designers who have come to Moscow, but his buddy is Thierry Mugler. "He is a beautiful boy. We are similar in temperament. He is abnormal, so am I. We are very intense. He designs and he photographs, I design and I photograph."

He has found no resistance here to his being a Soviet -- though he wonders if that isn't because he has been so well protected by his American connections. "I brought with me my best intentions," he said. "I have been told that competition is tough here and one must have sharp teeth to exist in this business. I am accustomed to being very sincere in what I bring forth."

And if he's not a big success here this time, it will not be a problem for him. "I'm not intimidated at all. Everything I make can be sold in Moscow."