Star Athletica began creating cheerleading uniforms with stripes, zigzags, and chevron insignia similar to those made by a Varsity subsidiary, but at a lower price.

The court ruled against the Guild, saying that its practice of attempting to create a monopoly outside the copyright system suppressed competition and violated the Sherman Antitrust Act.

[13] Some fashion designers bristled under the rules, wondering why other creative industries like films or music were allowed to restrict access to their products with copyright and they were not.

Trade dress required the public to recognize a secondary meaning associating the design with its origin, and was subject to contradictory rulings from the Supreme Court.

Varsity frequently filed lawsuits alleging infringement with accusations of general copying[10] to halt other companies from merchandising competing uniforms.

Instead of the majority's more-general assessment of athletic wear, McKeague would have defined the uniforms as clothing the body "in an attractive way for a special occasion" and "identify[ing] the wearer as a cheerleader;" their aesthetic features, therefore, could not be separated from the utilitarian.

On May 2 of that year, the court granted certiorari "to resolve widespread disagreement over the proper test for implementing § 101's separate-identification and independent-existence requirements."

[46] The Royal Manticoran Navy filed a separate supporting brief in Star Athletica which emphasized fair use in costuming, voicing a concern that allowing clothing-design copyrights would further strengthen Varsity Brands's position in the cheerleading industry,[47][48] one commonly described as monopolistic because of its 80-percent market share.

[47][57] Both criticized the "fast fashion" industry of duplicating expensive designs with increasingly-cheap 3D printing technology without payment to their original creators.

It pointed to a concession from Star Athletica that if Varsity (hypothetically) controlled The Starry Night, the company would be able to restrict the painting's printing on dresses.

The designs' colors and shapes were arranged to create optical effects such as the Müller-Lyer illusion, changing a cheerleader's appearance to make them look taller, thinner, and generally more appealing.

[63] Justice Ruth Bader Ginsburg rejected that line of argument, citing the fact that the examples presented in evidence were two-dimensional works.

For example, it was unclear how a decision in Varsity's favor might affect military-style camouflage patterns, and whether they could be restricted if fashion designs were copyrightable.

[69]After applying this test to the cheerleading uniforms, the court ruled in Varsity's favor that the designs were separable from the useful article and could be copyrighted.

The design needed to exist independently, and Thomas concluded that it did when it appeared in other media (such as the two-dimensional drawings submitted to the Copyright Office).

About Congress's reluctance to apply copyright to useful articles in general, Thomas said that congressional inaction was not usually a significant judicial argument.

[73] Thomas rejected the arguments of Justice Breyer's dissent and Star Athletica's similar contention that the designs were uncopyrightable because they would have the same outline as the useful article.

[69] Ginsburg's concurrence agreed on the second point in its notes; portions of Varsity's claimed uniform designs appear on other merchandise, such as T-shirts.

[66][79][82] Breyer then considered shoes painted by Vincent van Gogh and turned to the examples of Congress's intended targets of copyright in the amicus curiae brief filed by the Intellectual Property Professors.

Recent Congresses had rejected 70 bills to extend copyright to cover designs on useful articles, which he interpreted as an unwillingness of lawmakers to enact the change.

Varsity founder Jeff Webb said that it was a win for "the basic idea that designers everywhere can create excellent work and make investments in their future without fear of having it stolen or copied."

Susan Scafidi, founder of the Fashion Law Institute, had been involved with the case from the district-court level and was sorry that it had to go all the way to the Supreme Court.

[66][31] Negative effects on fashion trends (which involve some degree of copying basic styles among designers throughout the industry)[66][104][105][106] and an anticipated increase in infringement lawsuits have been speculated.

Columbia Law School professor Ronald Mann analyzed the decision for SCOTUSblog, saying that the court's opinion did not address the minimal threshold of creativity required for copyright restriction under Feist v. Rural.

Mann called Thomas's dismissal of the opposing arguments "half-hearted" and predicted that scholarly debate of the separability test's shift in copyright law would continue.

According to the Review, "These dicta imply that the independently existing work can have the shape and look of the article, evoke the same concepts, and even perform the same function and still be separable" (making it copyrightable).

[110] In February 2019, however, the Copyright Office's review board used Star Athletica as a justification for refusing to register the design of a work glove.

The office determined that the design was not sufficiently original to be copyrightable because its "common and familiar uncopyrightable shapes" conformed to the human hand "in the most predictable manner.

"[111] In 2019, the office's decision to register the Adidas Yeezy Boost 350 shoe design was considered a significant expansion of the copyrightability of useful articles in the wake of Star Athletica.

[118] Star Athletica caused uncertainty in the 3D-printing community;[120][121][122][123] 3D printing was a relatively-new field, and the rules could have outsized effects on the development of its cultural norms.