Of course, modest fashion isn’t universal in its rules or its politics. Muslim women adhering to the dress code are encouraged to cover their ankles and have sleeves up to their wrist, with only feet and face visible to the public. Hasidic women are required to cover the collar bone, elbows, and knees. While all the customs vary just a little—“Everyone has a different conception of what modesty is to them,” Albarcha noted—fabric choice, colors, and cuts offer a surprising number of unlimited options. In fact, bloggers across the religious spectrum continuously emphasize the freedom within being held to a dress code, often describing the challenge as “liberating” and “fun.”

That combination of freedom and restraint means there are huge avenues for business with modest fashion, particularly on a global scale. With a fast-growing Muslim youth demographic tuned into the latest fashions around the globe, a vast group of people is underserved by traditional fashion chains: There are nearly 800 million Muslims younger than 25, according to Shelina Janmohamed, vice president of Ogilvy Noor, an Islamic marketing agency.

“Not only do you have more Muslims to target, but they are increasing in numbers faster and they are young. And, contrary to a lot of expectations, they are interested in brands and they are interested in asserting some kind of individuality through what they purchase,” Janmohamed told Business of Fashion last year.

But the inclusiveness of the modest-fashion movement also means its appeal stretches beyond the faithful. Atheists are among the most vocally supportive on social media of modest blogs and Instagrams—a point everyone I spoke to made to me without prompting. “If you notice from our Instagram page, it’s not a small hobby,” Hecht said of Mimu Maxi’s social-media presence. “We’re not about being a fashion brand. It’s more about feeling good and being true to yourself, telling women to be authentic, genuine.”

This emphasis on authenticity in part explains another interesting variable in the modest-fashion trend: Part of its appeal to Millennials has hinged on its association with the nebulously defined “hipster” label. “[Hipsterism] is about being unique but not being too unique,” sociologist Kevin Lewis told me. “It’s marginal differentiation, where you want to be different enough from your peers but not so different that you want to be ostracized.”

Beyond Hipster Hijabi's name, there's the fact that Mimu Maxu is based in Brooklyn's Crown Heights—a neighborhood known as a rising hipster mecca as well as a home to a large Orthodox population. Consider the frequency with which “hipster” is appended to various religious identities (sometimes by members themselves): Mipsterz (Muslim hipsters), Jewish hipsters, and Mormon hipsters. The label "hipster," at the very least, is more inclusive and malleable than Abercrombie's preppy, "classic East Coast collegiate style of clothing."

Modest-fashion trendsetters like Mimu Maxi's Hecht and Notik don't shy away from the oft-scorned term the way their secular counterparts might. Before Refinery29 referred to the pair as "Hasidic Hipsters" in a video last year, the pair said they had never even considered the label. But, perhaps by dint of the cool factor or the broader sales appeal, they don't mind.

"People who shop with us who aren’t Jewish don’t really care about religion," Hecht said. "They just like the fabric and the cut. There’s Muslims who like us, atheist hipsters who like us. We’re not hiding who we are, and it’s cool.”

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