The 'third coast' in fashion sheds string-tie image

Don't let the Texan penchant for armadillo-head bolo (string) ties and skin-tight blue jeans fool you. And ignore those Dolly Parton and Willie Nelson dress-alikes, because there's a mainstream fashion industry here that is not only a pillar of the state economy but is probably a mainstay in your own wardrobe.

And don't turn up your nose just because your label says ''Jones of New York.'' Chances are it's Jones of New York via Dallas. And that expensive dress with the label of a chic local boutique on it could easily have been stitched right here in the Lone Star State.

From its genesis as a whistle stop on the early railroad lines where hunters sold their buffalo hides, the Texas apparel industry has developed into the state's fourth-largest business and the nation's third-largest garment market - behind only the sweaty bustle of New York's garment district and Los Angeles's sportswear-dominated California Mart.

Images of the Texas mystique, in which big and tacky play a heavy role, are not always those most likely to fit well in circles of haute couture. So the Texas links to blue jeans (El Paso is the self-proclaimed ''blue jean capital of the world'') and polyester pioneering (polyester, like much of the Texas economy , is a petroleum byproduct) have perpetuated a deceptive picture of this billion-dollar business.

Texas has stakes in two tiers of the garment industry - the $3 billion-a-year wholesale sales generated by the Dallas Apparel Mart and the $2 billion-a-year apparel manufacturing done in the state.

Most obvious is the Dallas Apparel Mart, a massive six-story maze of showrooms where almost every name in the clothing business has a rack of clothes on display for retail buyers to peruse. Manufacturing sales representatives from the budget lines to the one-of-a kind designer lines, which are locked up tight in windowless showrooms to prevent knock-off artists from stealing ideas, generate sales of $3 billion annually to retail store buyers.

The Apparel Mart provides a central market used largely by Midwestern and Southwestern retailers who find it cheaper and more convenient to buy their goods out of Dallas rather than travel to New York's hectic garment district every time the fashion season changes.

Less conspicuous, but certainly no less successful, is the Texas apparel manufacturing industry, which employs some 80,000 people in about 800 Texas plants. Because 95 percent of the business is privately held and does not report earnings, there are no exact sales figures. But Marvin Segal, an industry observer who formerly represented the Southwest Apparel Manufacturers Association, ''guesstimates'' that business runs at about $2 billion a year.

The Texas economy has attracted apparel manufacturers because of the state's right-to-work laws, the Mexican laborers in the area, and the easy marketing access offered by the Apparel Mart.

Like other industry officials, Mr. Segal, who calls Texas ''the third coast'' in the apparel industry triangle, does his best to head off any misconceptions about the clothing industry in Texas. Yes, he says, Texas is the blue jean capital. Yes, it has been a leader in synthetic fabrics and budget line clothes. But Texas is also a fashion leader in manufacturing, he contends.

That point is open to debate and largely depends on the very subjective definition of ''fashion.''

''I can honestly say there's not one person who counts as a fashion creator there (in Texas),'' sniffs a representative of the Council of Fashion Designers of America, an honorary group including such fashion heavies as Oscar de LaRenta and Bill Blass. She quickly amends that statement to add that Dallas evening wear designer Victor Costa does make the grade.

But Mr. Segal suggests that the haute couture's inner circle ''has a perspective that does not go west of the Hudson.'' And its designs arguably don't go much further than the Vogue magazines on America's coffee tables - that is, if practicality and the average consumer's pocketbook are factors.

''We're no longer the polyester capital of the world,'' Mr. Segal explains. ''We're geared to the average woman . . . we sell to the great Middle America.''

In fact, Mr. Costa, a Texas native and member of the elite Council of Fashion Designers of America, indicates that his line of special-occasion clothes, which retail between $100 and $300 in places like Lord & Taylor and I. Magnin, is designed for the average woman ''who is aware there are other things to spend money on.''

Further, says a writer for a national fashion publication, ''it boils down to the fact that nobody does anything original. Take a suit from Prophecy (a moderate-priced women's line designed and manufactured in Dallas) and put it next to Jones of New York and try to find the difference.'' With only subtle differences in style and quality, she suggests, there is perhaps nothing but name-recognition and price that distinguishes a Texas designer from a New York designer - at least in the eyes of the average consumer.

The cosmopolitan swirl that follows wealth has generated a fashion interest in Dallas, whose special tastes have always been catered to by the exclusive Neiman-Marcus department store. But now those tastes are being courted with enough of a variety of retail competition to bankroll the ad linage to support two weekly fashion sections in the city's two daily newspapers. (The Los Angeles Times, by contrast, recently folded its weekly fashion section.)

Further, local apparel industry officials are emphatic in their assertions that Texas has more consistently well-dressed and fashion-conscious women than even New York City. They also deny that cowboy chic, which integrates every hide imaginable into wearing apparel, is a large force in urban Texas - even though that look happens to be the first thing a visitor notices.

However, the number of high-priced boutiques and department store chains flourishing at local shopping malls - like the Houston Galeria, which is one of the nation's most fashionable - indicates there is the interest and the cash here to support a fashion industry of more than just cowboy hats and boots.