LOS ANGELES, United States — At the 89th Academy Awards in Hollywood on Sunday night—hours before everything went sideways on stage—Taraji Henson of Hidden Figures strode down the red carpet in a blue velvet gown from Alberta Ferretti that was dubbed "stunning" and "absolutely perfect." Emma Stone accepted the Best Actress award for La La Land wearing a glimmering bronze Givenchy dress. And Viola Davis of Fences delivered a moving speech clad in a blazing scarlet number from Armani.

The red carpet at the Oscars has its own dedicated television and web shows filled with fawning (and acidic) commentators. The moment an outfit appears from the backseat of a limousine, it’s scrutinised from all sides. Fashion critics dissect trends, glossies and cable squabble over who wore what best, and the labels try to figure out what’s catching on. It’s one huge advertisement, with celebrities paid to be runway models for a night and millions of captive eyes: If a dress or gown is a hit, dressmakers need to move fast.

As do the lawyers. The big fashion houses, some of which translate trends into affordable looks for retailers (few people are going to shell out thousands for a floor-length Valentino), must contend with unauthorised duplicates and adaptations that pop up in stores and websites almost instantaneously.

“Clothing design in the US is pretty vulnerable,” said Michelle Mancino Marsh, an intellectual property attorney specialising in fashion law at the firm Arent Fox. “It’s an art that doesn’t get respect.”

Protecting a Silhouette

The easiest thing to protect is a trademarked logo, such as Louis Vuitton’s famous “LV” or Versace’s Medusa head. Though it’s common for logos to appear on clutches or other accessories, rarely do they appear on swanky gowns, though.

Everything else is much harder to defend as uniquely your own, and filing for a design patent or copyright protection often doesn’t happen until well after a look’s first public appearance. By then it’s generally too late.

Silhouettes, perhaps by definition, are hard to protect, which makes it near impossible to claim that a strapless a-line dress is uniquely your own. But if it has some kind of distinctive flourish–say a standout sash or belt buckle–that can be protected under intellectual property law. Patterns, like a unique lace arrangement or floral configuration, qualify as well. (Something like John Galliano's tulle face design for Maison Margiela, for instance.)

Though many designers consider knockoffs the cost of doing business, bigger labels with deep resources are much more aggressive in protecting their turf. Every year, when the Oscars are over, armies of attorneys start a small war, said Marsh.

First come the cease-and-desist letters from the law firms, laying down the threat of litigation to deter less committed copycats who may not wish to spend on a costly defense. They also alert the retailers and the web commerce platforms, calling for items to be taken down from Amazon or Alibaba. But in  many ways, it’s simply a show of force to guarantee domestic offenders and retailers toe the line. Increasingly, the knockoffs are made and sold overseas, and thus harder to reach legally.

“The big dress manufacturers here in the US, they know the law,” said Marsh. “They’re usually careful enough to change the dress just enough to not be considered a knockoff."

A dressmaking label called ABS by Allen Schwartz once made a business of adapting Oscar looks for kids on prom night, but has since taken a new direction. “I didn’t like the publicity,” Schwartz told the New York Times in 2013. “It kind of takes away from the creativity.” Now the segment is ruled by online stores with generic names like World Celebrity Dress and The Celebrities Dresses, touting red carpet looks on the cheap and assuring shoppers that they can “dress like a star.” When fashion site Racked ordered looks from one of the sites, it found that the garments were well-made.

Red Carpet as Commercial Institution

Georgio Armani institutionalised the red carpet in the early 1990s, morphing the event into the spectacle we saw yesterday. Fashion houses saw how much buzz they could obtain by dressing celebrities, and dashed out to get their suits and gowns on the most influential stars.

“It’s bragging rights,” said fashion writer Teri Agins, author of Hijacking the Runway, How Celebrities are Stealing the Spotlight from Fashion Designers. “What designers want to do is be associated with celebrities because they’re the fashion role models for the consumer.”

Yet these days the red carpet is more public relations than sales driver, a long-term investment in keeping a label relevant and credible. However, it’s fair to say that no fashion label wants shabbier versions of its clothes out on the market.

More clarity on what makes a knockoff a knockoff may come from an unexpected source: a dispute over cheerleading uniforms. Varsity Brands Inc. alleged copyright infringement, saying that rival Star Athletica LLC's uniforms are too similar to its own protected designs. The case, now being heard by the U.S. Supreme Court, will determine when a design feature is protectable under the Copyright Act.

While the red carpet is all about brand image for the big players, for smaller designers, it can be a big payday. When actress (and former professional wrestling star) Stacy Keibler wore Naeem Khan’s black halter gown to the 2013 Oscars, it became the designer’s number-one gown globally. He sold 30 pieces at $9,000 per and received nearly 40 inquiries. “The exposure is great, no matter what,” he said. “And it often translates to sales.”

By Kim Bhasin; editor: David Rovella.