Ooh la la! No matter how many times a star in a see-through gown struts down the red carpet, the public tends to react with raised eyebrows and dropped jaws.

This awards season, from the Golden Globes to the Grammys, there was a particularly high volume of oohing and aahing from stargazers because many celebs have decided to go sheer this year, and the trend is trickling down to the public, too.

Why has the naked dress returned in 2020, more than five years after Rihanna brought it back and covered it in Swarovski crystals? Unlike the material on trend, the answer has a few layers.

The see-through trend isn’t exactly new

Gwyneth Paltrow made headlines when she wore a floor-length Fendi ensemble to the Golden Globes that was so see-through you could still see the sparkle of her diamond Bulgari necklaces even though they were underneath the high-necked dress. Jennifer Aniston’s name became the biggest search term from Screen Actors Guild Awards, partially because her white semi-sheer Dior gown had fans doing double takes. And many of the best-dressed stars at the Grammys, including Lizzo in an Atelier Versace gown dripping in crystals and Bebe Rexha in crystal mesh Christian Cowan suit, rocked sheer ensembles.

But before these stars showed skin, Rihanna bared her bod in 2014 at the CFDA Fashion Awards when she was appropriately honored with the Fashion Icon Award.

“The Rihanna look is the quintessential see-through look,” says Rajni Jacques, fashion director at Allure. The singer’s sparkling getup, which could've been made out of pixie dust (and was paired with a matching headpiece and boa), “was a big moment. Everyone goes back to that.”

Sheer clothing is on the runways and the streets

You’re not just seeing things: See-through fashion is red carpet staple this year, and also a popular runway look and street style. The trend “is kind of like the ‘90s (trend): It’s always cyclical,” Jacques says, adding that this year, the sheer trend was clearly “driven by awards season.”

In Tom Ford’s Fall/Winter fashion show, supermodels Bella Hadid and Gigi Hadid wore a revealing silver chain mail dress and completely see-through black lace gown, respectively. At Jason Wu’s New York fashion week presentation, models walked in brightly-colored dresses with nude undergarments visible.

The naked dress even made its way on the reality TV catwalk recently. In Netflix’s series “Next In Fashion,” a design team tasked with producing a red carpet look opted for a twinkling silver dress made with semi-sheer fabric and side cutouts. Supermodel co-host Alexa Chung smiled as she described the look as “subversive” and “dangerous.”

“Designers get inspiration from what they see on the street, and (shoppers) get inspiration from storefronts,” says Jacques about how different components of the fashion industry influence one another. “Each looks to the other to figure out what they’re wearing the next season, and tomorrow.”

And online shoppers are trying out the trend. In the last month, compared to the same time last year, searches for “sheer” and “see-through” products have increased more than 150% on shopping website ShopStyle.com.

It fits young people's 2020 ethos

It takes a certain kind of confidence to wear an outfit that might display intimate freckles, cellulite, undergarments or even nipples. But celebrities and brands have helped spread a body positivity movement that is resonating in fashion.

“Show your body, feel good, you know what I mean?” Rexha told USA TODAY on the Grammys carpet. “Except for the eight pounds of tape that I have holding up my boobs.”

The message of confidence (and comfort with oversharing) is part of the Millennial and Gen Z ethos. So it’s fitting that those are also requirements of wearing sheer clothing.

How to wear sheer everyday

You don't need to have a gala invite to wear a sheer outfit. Young shoppers, who tend to be green-minded, are browsing the "wearable sheer" (as Jacques describes it) dresses that sustainable brands including Christy Dawn and Reformation are putting out. These clothes are only see-through when light hits them in a certain way.

Other ways to show off sheer: Wear biker shorts with sheer overlay, or bralettes under see-through tops with jeans.

In the near future, Jacques expects to see online retailers including Fashion Nova and PrettyLittleThing sell thin camisoles inspired by the lacey fabric in Rooney Mara’s sheer Golden Globe outfit, and fringed shirts inspired by Lizzo’s Grammys dress.

“It’s all a symbiotic dance,” she says. In this case, it could be a nearly naked one.