It was 4 p.m. on the eve of the first day of Fashion Week and Alfred Fiandaca was four stories above 36th Street doing something that’s become increasingly rare in the swath of Manhattan known as the garment district: He was working on a garment.

In one corner of the room, Mr. Fiandaca — known for dressing many a grande dame, including Nancy Reagan and Audrey Hepburn — was pinning an amber-hued, long-sleeve gown on New York arts patron Ethelyn Chase; in another corner, his publicists inspected the seating chart for the next day’s show, alternately grumbling and enthusing over certain names. In a room just off to their left were five women on sewing machines, a cutter, a pattern maker, and a passel of young assistants putting the finishing touches on dresses, some of which would be hanging on models some 10 blocks away in just a matter of hours.

For much of the 20th century, the neighborhood bounded by 34th Street to the south, 40th Street to the north, Ninth Avenue to the west, and Broadway to the east housed numerous operations much like this, as well as the myriad wholesale shops and contracted sewing and cutting factories that made up the country’s fashion industry.

“You need some apparel production and suppliers here to keep the ecosystem of the garment district,” the head of the fashion-retail office at the city’s Economic Development Corp., Patrick Murphy, said.

In recent years, rising Midtown rents and inexpensive overseas labor have compromised this delicate balance. Local garment manufacturing has been steadily shrinking, despite city zoning that puts certain limitations on how many residential and non-garment businesses landlords can allow on the neighborhood’s side streets.

“This is an area where people used to always be well-dressed,” Mr. Fiandaca said. “There were always expensive dress racks going down the street.” Today, however, you’re more likely to find hot dog vendors and cheap bolts of rayon.

Some designers are nevertheless doing what they can to help sartorially discriminating New Yorkers wear locally sourced threads. At least a couple dozen of the designers showing this week, including Nicole Miller, Zac Posen, Marc Jacobs, and Nanette Lepore, still produce some part of their lines on streets just a $4 cab ride from the Bryant Park tents.

“Has the flavor of the garment district changed? Yes. It’s become more corporate today. There’s a much more diverse mix of businesses that have come into the area,” the chief executive officer of Bill Blass, Michael Grovemanwhich, said. His company still makes much of its line at 550 Seventh Ave. — the avenue known, of course, as Fashion Avenue — in the same building where it also has its corporate offices and showroom. Any items that weren’t stitched there were most likely cut and sewn at a contracted factory within a three-block radius.

“A lot of our contacts have had to consolidate and move to other areas. Two of our contractors now have to share a space in order to afford to be there. But we don’t plan on going elsewhere,” Mr. Grovemanwhich said. “Most of what we make is made to measure and it’s important to have hands-on access, and we’re very happy with the work we get done in this district. These manufactures have been working for us for generations.”

Although few young designers opt to put their offices or showrooms in an area that, in the opinion of at least one industry insider, “has all the aesthetic appeal of an armpit,” emerging designers rely on the contractors in the area to help produce smaller labels.

A co-founder of the year-old line Bensoni, Benjamin Clyburn, spends most of his days overseeing the work being done by cutters and sewers in the area. “It’s a pretty gritty place, but there’s this hustle and bustle that makes it feel exciting to be there,” he said. “You feel like you’re getting something done.”

Nili Lotan, who was granted a spot in Fashion Week after winning a recent contest organized by Mercury Mariner and Hachette Filipacchi, has been producing her eponymous label at factories in the garment district since 2004. “You can respond very quickly to reorders, or to any problems that might come up in production. It’s too hard for a small company to have that kind of communication with factories overseas,” she said. “The disadvantage of course is the price. Obviously you are paying more to be here. When you look at who is manufacturing domestically, it’s usually small designers who are at the earlier stages of the business. I would like to see myself growing here, but often what’s most important is the bottom line.”

Of course, not all the “Made in NYC” garments on the Fashion Week runways came from the garment district. According to a project manager for the Garment Industry Development Center, Magda Aboulfadl, 40% of the clothes that comprise New York City’s $47 billion fashion market are now made in the outer boroughs. “There are about 13 buildings where cutters and sewers are located in the garment district — about 1 million square feet of factories. The next highest concentration of factories is in Long Island City and Sunset Park,” she said. “Eileen Fisher is in College Point, Queens; Oscar de la Renta is in the Bronx.”

Mr. Fiandaca, whose headquarters is a stone’s throw from several wholesale ribbon stores and sewing supply shops, has no plans of moving out of the country — or even out of the borough — any time soon. “It may be a little more expensive to be here,” he said. “If I were elsewhere, where would I go if I needed chalk?”