It's Saturday and most city dwellers are relaxing. But not Robert Lee Morris. Dressed in baggy black pants and a shirt with rolled-up sleeves, the young artist is attaching fasteners to necklaces and clips to earrings with lightning speed.

"Donna's sending her driver over for these things in just a few minutes," he explains. "You'll have to excuse me while I finish."Donna is, of course, Donna Karan - one of the hottest designers on Seventh Avenue right now. And Morris is doing the jewelry to complement her fall collection - strong, bold accessories featuring burnished metals and hand-set stones.

For several seasons now he has collaborated with Karan, making special necklaces, bracelets, pins and earrings to accentuate her stellar styles. Together the two have been dynamite, garnering all kinds of headlines from the fashion press. Yet, long before Karan came along, Morris was a star. Winner of the Coty Award, recipient of honors from the Council of Fashion Designers, the artist dazzled the apparel industry with his originality and innovation virtually from the moment he first appeared on the scene.

Just what made - and still makes - the work of Robert Lee Morris so significant?

Simply this: The man has redefined fashion jewelry and given it new status and respectibility as art. Furthermore, his pioneering work and the gallery he has established to promote the concept have paved the way for other talented young people longing to make fashion their canvas.

Morris calls the concept "Artwear" and notes that it can include any facet of fashion, but primarily focuses on jewelry and accessories that have a life of their own. It projects a distinct feeling and mood just the way painting and sculpture do and is composed of many of the same elements found in the fine arts.

The arts attracted Morris early in life, and he soon made up his mind to establish a career in that area. At first filmmaking was his goal, and he took several courses in the subject at school.

After graduation, his interest in film waned. He established a commune and began teaching himself how to make jewelry. "Everybody was doing something arty, and I needed a creative outlet," he explains.

He was a natural, and his expertise grew, eventually blossoming into a business in Vermont. And it was in Vermont that he was discovered by representatives of Sculpture to Wear, a boutique located in the posh Plaza Hotel in New York City.

At the boutique, Morris' work was displayed right along with Picasso's gold pendants, Calder's brass collars and Man Ray's earrings. But there also were "unknowns" who were featured, such as Ted Muehling and Cara Croninger.

"I learned to admire the things Ted and Cara were doing and to appreciate their artistic courage," says Morris. "When Sculpture to Wear closed, I decided to make a commitment to them and other young talents by opening my own gallery."

Morris dreamed up the word Artwear and it rapidly became recognized by leading fashion designers, editors and the public. In 1978, the gallery moved from Madison Avenue to Soho's West Broadway.

The clean, sculptural design of the Soho gallery attracts both the serious patron and the curious tourist. But it's the diversity of the work found inside that's truly memorable.

"We've had a bit of everything over the years," says Morris. "My things, which are dramatic, sensual and usually done just in metals. (The fall Karan collection incorporated stones for the first time). Ted's work, which is more refined, and Cara's, which focuses on acrylics, polyester resins and unusual materials. There have been a number of other artists whose work has been featured, too. But I really think that the first group - the ones we started out with - remain the most individualistic and outstanding."

There have been up to 50 artists represented at Artwear at one time, although there are considerably fewer right now. Morris says 50 was too many and the gallery was a nightmare to manage because not all the tenants were dedicated to art and perfecting their craft.

"We insist on a solid, sincere commitment now," the gallery's founder says. "We also want people who are doing innovative things that are totally different from what's already being displayed and sold. Finding these people isn't easy, even though there are more producers of wearable art today than ever before and our gallery has become just one of many all across the country."

Acting as curator of the gallery and a subsidiary in uptown Manhattan keeps the jewelry designer extremely busy, as does his own artistic career.

Six to 8 collections of jewelry are produced each year. Morris also lectures frequently to students on art and being an entrepreneur; is doing handbags, cashmere scarves, belts and hair ornaments, and recently introduced a line of luggage and a fragrance, "Verdigris."

"I thrive on new challenges," says the man who started the art-to-wear movement.