On a recent Sunday on Howard Street, a well-lit 1,900-square-foot store became a brief sanctuary from the paparazzi. Rihanna swooped into Reformation, grabbed a pile of clothes, retreated to a dressing room and, within minutes, walked out with a new coat and 14 dresses, sweaters and tops. It cost her a little more than $2,000.  This isn’t all that uncommon: Rihanna has been to Reformation — there are two stores in New York and one in Los Angeles — before for a quick shopping spree. Taylor Swift shops there. As does the model Karlie Kloss.  “It’s funny, I have access to some of the most beautiful clothing in the world, some of the most expensive, elaborate couture pieces, and yet in my daily life I wear Reformation,” Ms. Kloss said, when she was buttonholed at a private dinner last month. “It’s very simple and it’s cut really well.”  It’s not just stars and models. Attend a New Year’s party or an office holiday party in New York or Los Angeles in the coming days and you’ll likely find a girl wearing Reformation. Every few years, a cheerful label emerges that the cool girls in the city flock to, whether Opening Ceremony when it debuted in 2002, Topshop a few years ago or Juicy Couture in the late 1990s. For a certain urban sophisticate who is tall — let’s say about 5 foot 6 to 5 foot 10 — and thin and in her 20s, this has become the an affordable-ish uniform of 2014.  But first, it had to get a makeover. Founded in 2008, Reformation spent the first five years of its existence as a modest business. In the last 12 months, it has blown up. Last year it had about $9 million in revenue; this year it will do better than $25 million, said its founder, Yael Aflalo. Those sales are built by the power of its dresses, crop tops and A-line miniskirts that generally range from $80 to $300. They are also eco-friendly, relying on sustainable and vintage fabrics. When a customer walks into Reformation’s SoHo store, these are the words that greet you: “Change the World Without Changing Your Style.”  “I want altruism and narcissism to be combined,” said Ms. Aflalo, a Los Angeles native, in an interview at Le Pain Quotidien on a recent trip to New York.  This isn’t the first time Ms. Aflalo, 37, has built a fashion business, even if she is an unfamiliar name within the fashion world (even in Los Angeles). She founded the label Ya-Ya in 1999, which, at its high water mark around 2005, was earning more than $20 million a year.  Ms. Aflalo credits a Zara-like fast fashion model for Reformation’s success. She wants her clothes in and out of her store and on and off her website as quickly as possible. (A few weeks ago, she hired Zara’s trend director, Manuel Ruyman Santos, to become Reformation’s design director.)  “The most important thing to me was speed,” she said. “Speed to market. I knew that if I had speed I could control inventory problems. Something I learned from my last business is inventory will kill you. It’s the biggest nightmare.”  There were a lot of lessons from that previous business that have helped her turn Reformation into a success. She founded Ya-Ya at age 21 and was part of a wave of designers who made their name after getting a push by the Los Angeles retailer, Fred Segal.  “Young girls would literally come off the street and come in with collections,” said John Eshaya, the head buyer for Fred Segal at the time. “Either I’d buy it or mentor them, and in return it gave us new designers that nobody else had.”  At Mr. Eshaya’s encouragement, Ms. Aflalo created a collection, it took off and before long she was making “considerable money,” she said.  “I bought a big house, I had more than one car, and the cars were convertibles,” she said, “and I had parties, and I would go on long design vacations.”  It didn’t last. The relentlessly hard-charging and unforgiving fashion schedule drained her. She got sick of forecasting designs 18 months before it would hit the stores. Then the recession hit.  “The markdown agreements started coming in from the department stores, and all the boutiques were closing, and they couldn’t pay their bills,” she said. “You have accounts receivable that just disappeared overnight. I said I can either fight to keep this business alive or I can just close it.”  She closed it and fell into debt with suppliers. She let her staff go and kept three people around. She decided to make the smallest of comebacks: She took vintage dresses and customized them. She opened up a store for those dresses and called it Reformation. She cobbled together another $25,000 and added a store in New York.  “They popped off,” she said. “I thought there was no way in hell that this store was going to make money. I thought it might eke by.”  She started doing dresses and tops for Urban Outfitters, and before long, her debts were paid off.  “I had stores in New York and Los Angeles, I was happy,” she said. “I didn’t work that much. The stores were fun. I could afford the lifestyle I wanted to have. Then I went to China.”  After her trip to China, she had an awakening and described the harmful effects that producing and manufacturing clothes had on the environment. Reformation was about to go in a new direction.  “I realized I could build a business that solved these problems,” she said.  AS GRANDIOSE AS that plan was, it forced her to create a bigger business, one that wasn’t relying on orders from Urban Outfitters or a small retail business with a couple of stores. One wondered if perhaps she was tapping into an increasingly popular desire to be eco-conscious. Was this just an elaborately dressed up marketing plan?  “It’s not a marketing thing,” she said. “It’s fortuitous timing.”  She had to figure out where she could make her clothes with the sort of the sustainable materials she wanted to use. In her previous business, there were plenty of manufacturing headaches.  “I was constantly fighting with the factory,” she said. " ‘You didn’t do it right, it’s late, give me back 20 percent.’ And then it was a feeling of like: I don’t want to fight with these people anymore. I want to control how our clothes are made.”  She opened her own factory with her own workers and that provided her flexibility she never had in her previous business.  “How we were able to really grow the business was if something’s doing well, I can get it back onto the floor in two weeks,” she said. “If yellow’s doing well, I can get more yellow in a few weeks. If green’s not doing well? Green’s off the line.”  Some might question whether a fast fashion model and eco-consciousness are in any way compatible, but she has received a warm reception from advocates. Reformation recently finished as a runner-up in a Council of Fashion Designers of America eco-fashion challenge.  “Right now, there’s an appetite for fast fashion and clothes that are inexpensive and have style,” said Julie Gilhart, a fashion consultant who is outspoken about eco-fashion. “I can’t fault her. She’s gaining traction, she’s getting girls to wear her clothes, and she’s talking about this. It’s a much better way to approach fast fashion than some of the other fast fashion companies that aren’t doing anything or aren’t talking about it as much.”  If there is one place where Reformation really picked up steam in the last year, it is its online store. As late as February 2013, Reformation did only about $19,000 in sales online.  “Online you don’t sell clothes, you sell images,” she said. “We always did well in the stores, but we didn’t know how to present ourselves online. E-commerce? People are always standing like this.”  Her whole body went stiff, and she stared a blank stare.  “We put up an editorial image where, like, her hair was in her face and she was moving around,” she said. “And then all of a sudden that started selling way better. I was like, ‘O.K., let’s just make all the pictures like that.’ ”  Specific looks and poses emerged online: If there’s a skirt, she’s twirling (“Twirling is big,” she said); if there’s a jacket, she’s looking down (“Leather jackets, they’re all looking down.”). By last month, Reformation was doing $1.6 million in sales online, she said. The online business now represents about 65 percent of all revenue.  THE REFORMATION LOOK, both online and in the stores, has a vaguely scattershot vintage feel to it. On Monday night at the SoHo store, Sade’s “ Sweetest Taboo” played from the speakers. Hangers are built to accommodate retro shoulder pads. Reformation’s New Year’s Eve collection is inspired by the 1970s. Mel Ottenberg, Rihanna’s stylist, said that when he was looking at Reformation’s clothes, “it looked like it came right off the set of ‘90210.'” (Ms. Aflalo grew up in Beverly Hills).  When Mr. Ottenberg was working on a Rihanna Rolling Stone cover last year, he put her in a Reformation jumpsuit. “I wanted something really pure and easy,” he said. “And when you want something like that, it’s really hard to find. Sometimes designers struggle with that. We were looking at this rack of stuff, and that $75 jumper was the only thing we tried on. It was simple and easy, and this line gets that.”  Likewise, Ms. Kloss talked about how comfortable the clothes made her. “My favorite thing is to wear Reformation in the summer,” she said. “I live in those dresses in the summer.”  Ms. Aflalo said that summer designs are by far the best-selling season for Reformation, but with her sudden windfall she hopes to change that. Sweaters are being introduced, as are more coats. But she is still focused on her bread-and-butter: those dresses. And if there’s one thing she really wants to maintain, it’s their uniqueness. There are rarely more than 40 units per style per color, she said.  “One of the things that’s important to me is that when girls go to a party, I’d like to limit the chance that a girl will be at a party wearing Reformation and run into another girl that has the same dress on in the same print,” she said.  That might get harder to pull off.  A version of this article appears in print on December 18, 2014, on page E1 of the New York edition with the headline: An Eco Label the Cool Girls Pick. Order Reprints| Today's Paper|Subscribe
A clothing store that counts models and stars (including Rihanna and Taylor Swift) among its customers, touts inexpensive fast fashion, and is eco-conscious as well.