LONDON, United Kingdom — Something curious has happened to the fashion industry in the last few years: So-called modest fashion has started to take off. Designers and retailers are producing clothing that's often a little longer and slightly looser and tends to have a higher neckline.

That’s good news for an eager generation of young women who want to look great while respecting their religious values.

Burberry, DKNY, and other brands have released special Ramadan collections, timed to coincide with the Muslim holy month. Uniqlo sells a line from British designer Hana Tajima described as fusing "contemporary design and comfortable fabrics with traditional values." And last month, an event billed as the first "modest fashion" week was held at the Saatchi Gallery during London Fashion Week.

Behind this shift in tastes and preferences are a cadre of amateur designers and bloggers who amassed millions of followers on social media and grabbed the attention of big brands.

“It’s not like we just started to wear hijab,” said Mariah Idrissi, 24, who in 2015 became the first person to wear a hijab in an H&M ad campaign. “We’ve had this industry for a very long time, and they never really took notice.”

That seemed to change after bloggers proved they could attract huge followings.

Dina Torkia, 27 years old, started out posting pictures of her own clothing designs on Facebook five years ago, but people kept asking about how to style a hijab. She turned to YouTube, where she showed people how to create a “volumized” style. In one video, she showed viewers 20 different ways to tie a scarf.

“Think of it like a haircut,” she said. “People get bored of their hairstyles, so we get bored of our hijab styles.”

Torkia—known as Dina Tokio to her 1.1 million Instagram fans and more than half-million YouTube subscribers—blogs about finding clothes that reflect her faith-based values of dressing modestly. She has released her own lines and worked with a number of brands, including London high-end department stores Liberty and Harvey Nichols, as well as French luxury house Lancôme.

The market has been obvious for years. In 2015, Muslim women are estimated to have spent $44 billion on modest fashion alone, according to a Thomson Reuters report. Muslims make up 23 percent of the world's population, and the Pew Research Center expects the figure to grow to 29.7 percent by 2050.

Religious women—not just Muslims, but Jews and Christians as well—have long struggled to find clothes that are both modest and trendy. Rabia Zargarpur, one of the pioneer designers in the modest-fashion world, said that when she started wearing a headscarf around 2001, she drew styling inspiration from Erykah Badu, who isn't Muslim. In 2009, Zargarpur opened an online store selling her own designs, including long-sleeved shirts and tops that would cover hips.

Zargarpur—or Rabia Z as she’s known—showed off her first runway collection in 2007 at the Dubai International Fashion Week. Big retail brands started to get in touch, but she said she thinks they weren’t ready to make the leap. “The regional stores were super-excited because they knew that it would sell well,” she said. “But I would go to headquarters, and they would always hesitate. They said ‘Oh, we’re busy with other projects,’ but I know that it was the hijab aspect.”

It was around the time Torkia started posting her designs on Facebook that some of today’s most prominent fashion bloggers started to express themselves online. Kuwait-based Ascia al-Faraj, 27 years old, started blogging in 2012 and has quickly become one of the region’s most influential fashion writers, amassing more than 2.1 followers on Instagram.

Al-Faraj has worked with a series of premium brands, but her latest collaboration is with Net-a-Porter, the online luxury retailer, which she first hinted at online while posing with Gucci handbags.

Robbie Sinclair, womenswear editor of the trend-forecasting service WGSN, said that beyond the potential for sales growth, companies are purposefully trying to stand out by making bold statements that can veer into the political realm.

Nike released two ads in February featuring women wearing headscarves. The company also changed its bio on Twitter to simply read: “If we can be equals in sport, we can be equals everywhere.” The second targeted the Middle East and highlighted five female athletes from the region.

Sinclair said it's only a matter of time before more companies incorporate modest fashion into their collections. “Something's always just an idea until someone does it,” he said.

It's more than just headscarves. While the event in London mostly attracted Muslim women, Torkia thinks modest fashion can be for anyone. “I think we need to take Muslim out of it,” she said. “I’m pretty sure every religion promotes modesty.”

By Siraj Datoo; editor: Lisa Fleisher.