Items from the Jamie Johnson's Black Sweater collection and Alexander Olch's spring collection. Astrid Stawiarz for The Wall Street Journal

As we all well know, this city is about fulfilling certain niches. Alexander Olch and Jamie Johnson happen to be two documentary filmmakers who are also interested in the well-dressed man. They are so interested, in fact, that they each have their own fashion line.

Mr. Olch is the director of "The Windmill Movie," which is about the life of the filmmaker Richard P. Rogers. For several years now, Mr. Olch has been the driving force behind Olch, a line of silk, cashmere and woolen neckties. Lest you think that only big corporations understand the value of synergy, Mr. Olch has designed a superfine English Repp woven silk tie with windmills on it that is "the official necktie of 'The Windmill Movie.'" It is available by special order on his website.

Stephanie Lacava Astrid Stawiarz for The Wall Street Journal

Jamie Johnson and Ivanka Trump Astrid Stawiarz for The Wall Street Journal

Olivia Chantecaille Astrid Stawiarz for The Wall Street Journal

Charles Rockefeller Astrid Stawiarz for The Wall Street Journal

Jamie Johnson and Alexander Olch Astrid Stawiarz for The Wall Street Journal

Mr. Johnson, on the other hand, is the great-grandson of Robert Wood Johnson I, co-founder of Johnson & Johnson. He is perhaps better known as the director of the film "Born Rich." (He also went to high school with this reporter.) "Born Rich" included interviews with Ivanka Trump, Josiah Hornblower and Georgina Bloomberg as they discussed what it was like to be born into money. Lately, however, Mr. Johnson has spent time grooming a line of tailored men's clothes called Black Sweater.

With such similar interests, it is not surprising that Mr. Olch and Mr. Johnson would become friends.

"When I was trying to finish my movie, I hit a roadblock creatively and Jamie really solved some problems for me," Mr. Olch said. "We're both interested in certain stylistic vestiges of the past. And as a documentary filmmaker, you get used to making things for yourself, so you wonder: 'Could I make a collection of clothes, too?'"

This was on Wednesday—yes the night of springtime hail—on the third floor of the Bergdorf Goodman men's store. Mr. Olch was celebrating his new collection of ties as well as this week's DVD release of "The Windmill Movie." Mr. Johnson was introducing the first pieces from Black Sweater. There were lots of preppy and fashionable folks milling about partaking in Irish whiskey-flavored cupcakes with camouflage decorations on them.

Many of these preppy and fashionable folks would have to be born rich or, separate from any inheritance, doing relatively well financially, to enjoy Mr. Olch's and Mr. Johnson's luxury offerings. Nestled near the $1,240 Balmain motorcycle pants were Mr. Olch's lovely skinny $140 ties as well as a $2,500 trench coat from Mr. Johnson's line and what is his new trademark: a $695 V-neck black sweater.

There is a story behind the "black sweater." Permelia Reed, who had helped found Jupiter Island in Florida with her husband in the '30s, would banish people from the community by sending them off with a black sweater. According to Spy magazine, the black sweater first appeared in the 1950s when Mrs. Reed covered a woman showing too much cleavage at a club dance with her own black sweater, and "the sweatered woman was off the island the next day."

"It's become genuine folklore," Mr. Johnson said. "I believe tablehopping at a dinner party was enough to get you a black sweater. But I've heard worse stories: if a woman was wearing too revealing of a bathing suit at the beach or if she was having an extramarital affair. I was also told the sweater was cashmere. Such was the life in resort society." (Reporter's note: Sending someone away with a cashmere sweater seems like an extraneous financial expense. And remember, this was before cashmere hit Costco. )

"I heard of someone getting a black sweater on their doorstep in Greenwich, Conn.," said the banker Ren Grady.

"You did?" asked his wife, the cosmetics scion Olivia Chantecaille.

What did they think was the contemporary equivalent of getting a black sweater? "Maybe a bad Page Six item," said Mr. Grady. "Or a nasty tweet or something on a blog."

"I hadn't heard any of this before," said Charles Rockefeller. "But I'm going to be pleased each day from now on that I don't get one."

"I've never gotten one," said Mr. Olch. "But I did move recently, so it's possible someone sent it to my old address."

"The truth is, I see these upper-class idiosyncrasies with a playful sense of irony and mischief," Mr. Johnson said. "Of course, there's an absurdity to someone being so attentive to etiquette that they would want to banish someone from society. Commenting on that is fun."

There was a dinner following the department-store cocktails at a nearby restaurant called Desmond's, where deviled eggs, fish cakes and a drink called the Brixton, made of pineapple juice, vodka and ginger beer were served. (Online, the restaurant has already been called a contemporary Stork Club.) But before heading over, Mr. Johnson said he felt the contemporary equivalent of the black sweater was telling people, in jest, they were going to get one.

"If you cheat at tennis, you might say, 'You're getting a black sweater,'" Mr. Johnson said, grinning. "That said, I'm going to get a real kick out of gifting them around town."

Write to Marshall Heyman at