WALL STREET JOURNAL | CHRISTINA BINKLEY

Among the fashion deities and style editors seated at the Thakoon show this week was a besuited gentleman dressed more for the United Nations than New York Fashion Week: Piriya Khempon, the consul-general of Thailand.

"He is like an icon" in Thailand, said Mr. Khempon of designer Thakoon Panichgul. The diplomat appeared in the sea of fashionistas because, he said, Mr. Panichgul could be a diplomatic and economic boost to the country where he was born.

That might sound like a tall order for a 35-year-old designer who is most widely known for the red-and-black dress worn by Michelle Obama at the Democratic National Convention in 2008. But Mr. Panichgul is proving to be a rare sort of designer—one with enough business savvy to have hired a sales staff even before pattern-makers and seamstresses when he started his label six years ago.

For a season or two after his burst of Obama-related fame, Mr. Panichgul seemed to use Mrs. Obama as his muse, and his collections appeared aimed at one high-profile customer who wears a lot of nice dresses.

This week in New York, though, the designer went in an entirely different direction. Opening looks in the collection were white, and tailored—including a stunning double-breasted suit. White was Mr. Panichgul's response to the camel colors being so heavily promoted for fall. "I've been sick of camel for the past year," he said in his studio a few weeks before this show. His dog Stevie, a tiny Yorkie-Chihuahua mix, was yapping around his ankles.

The collection moved on to sexier looks and juxtaposed girlish white cotton eyelet with vampy hook-and-eye enclosures that in some cases ran the length of the garment. That's the sort of thing that has earned the Thakoon label critical praise—its familiar and flattering silhouettes sparked up by unexpected or daring finishing details.

"I'm not an artist, I'm a designer," said Mr. Panichgul. "Designers are supposed to look at culture and solve problems."

These days, Mr. Panichgul is competing for adoration with newer, younger designers such as Prabal Gurung and Joseph Altuzarra. At a time when retailers are chasing the newest thing every season, he is neither the latest flavor nor the famous-as-Kleenex likes of Ralph Lauren or Michael Kors.

Mr. Panichgul works from a studio in New York's SoHo neighborhood, with offices cut out for him and his chief executive, Maria Tomei Borromeo. It's so crowded that when a summer intern arrived on her first day this year, Ms. Borromeo said, she looked around and exclaimed, "This is it?"

That's a step up from the meatpacking district garage from which Mr. Panichgul sold his first collection in 2004—10 garments that he made without telling his family for fear they would disapprove of his new career.

"I went to business school because my mom wanted me to take a scholarship. I didn't want to do business, but I was good at it," he said. His mother, a seamstress, brought him and his brother Kritsada from Thailand to Omaha, Neb., as boys. "Asian parents want their kids to be doctors. You feel that pressure," said Mr. Panichgul, who said he is very close to his mother and brother.

Fashion was his hobby. He adored European minimalist designers Helmut Lang and Jil Sander. School was awkward. "I always felt like a mutt. I was born in Thailand, grew up in Bangkok, moved to Omaha at the age of 11 and had to deal with the friends thing—all that."

After graduating from Boston University, he worked a stint in editorial at Harper's Bazaar, where he says he met Chicago boutique owner Ikram Goldman and others who helped him learn the ropes of fashion. He lived frugally and saved money. "Someone told me I lived like a monk," he said. His mother found out he'd quit his job to launch a line when she called Harper's Bazaar two months later and learned he was no longer employed there.

"It was kind of surprising for me and my mom," says Kritsada Panichgul, a food photographer who has worked with celebrity chef and cookbook author Rocco DiSpirito. "I should have known. When we were kids, we would go to the newsstands and he knew exactly when the new [fashion magazine] issues came out. He would get really excited."

Thakoon Panichgul, who said his mother is shy about her English and prefers not to speak with the press, noted that she swallowed her worries about her son's ability to support himself and has been "very supportive." (As usual, his very pleased mother was at this week's show, bowing shyly as she met guests.)

Mr. Panichgul was completely inexperienced that first year. "He didn't know the prices" of his own collection, said Ms. Borromeo, who joined him that season at Ms. Goldman's prompting.

In those early days, Ms. Borromeo said, Mr. Panichgul "would give me his chair and he would sit on an overturned garbage can."

Robert Burke, then an executive with Bergdorf Goodman's, remembered sitting at a folding card table to write up a small order with the first-season designer. "There are a very few designers who you look at and just know they're going somewhere." Mr. Burke called Thakoon well-priced for the luxury segment, with dresses in the $800 range—well under the $1,200 and up that many designers charge.

Ms. Borromeo declined to cite the company's annual revenues, but said this spring's sales were up 63% over last spring. A secondary line was launched last fall called "Thakoon +", which they refer to in the office as "Addition." Addition reaches a broader audience, with prices that run $195 to $1,000, compared with prices starting at $295 and rising to the sky at the main Thakoon line.

"He's a fresh, young, established, seasoned designer, and only today could you use those adjectives altogether," said Mr. Burke, who is now a fashion-business consultant.