Overview
On June 27, 2025, Lululemon Athletica Canada Inc. and Lululemon USA Inc. filed a lawsuit against Costco Wholesale Corporation in the U.S. District Court for the Central District of California (Case No. 2:25-cv-05864). The complaint alleges that select Costco private-label and third-party garments unlawfully copy Lululemon’s activewear designs associated with the SCUBA hoodies, DEFINE jackets, and ABC pants.
Lululemon asserts claims under the Lanham Act (trademark and trade dress), design patent infringement (including U.S. D989,442 and U.S. D1,035,219 covering SCUBA designs), and California’s Unfair Competition Law. The filing highlights a growing issue in fashion law, how trade dress, trademarks, and design patents apply to apparel designs in an era of widespread “dupe” culture and private-label retailing.
Timeline and Procedural Developments in the Lululemon v. Costco Lawsuit
June 27, 2025 - Complaint Filed
Lululemon accuses Costco of trade dress infringement, design patent infringement, trademark infringement, and unfair competition.
The complaint identifies several garments sold through Costco’s private-label and third-party lines, including the Danskin Ladies Half-Zip Hoodie, Danskin Ladies Half-Zip Pullover, Jockey Ladies Yoga Jacket, Spyder Women’s Yoga Jacket, Hi-Tec Men’s Scuba Full Zip, and the Kirkland 5-Pocket Performance Pant.
According to Lululemon, these garments closely imitate the seam placements, zipper configurations, silhouettes, and other visual elements that characterize its well-known activewear designs. The company seeks both damages and injunctive relief to prevent further sales of the allegedly infringing apparel.
July–August 2025 - Coverage and Discussion
Mainstream and trade outlets covered the filing, summarizing the asserted rights and accused products. Public commentary examined whether specific apparel elements are ornamental (and protectable) or functional (and therefore limited) in trade dress protection.
September 2025 - Early Case Activity
Public docket snapshots reflect an active case in the pleading stages. Commentary discussed potential defenses, including functionality, lack of distinctiveness/secondary meaning, and no likelihood of confusion.
October–November 2025 - Ongoing Proceedings
As of November 2025, the matter remains pending in federal court. Anticipated discovery areas include comparative design analysis, consumer perception evidence, and sales and channel data relevant to confusion and damages theories.
Types of Expert Witnesses in Fashion and Trade Dress Litigation
1. Design and Industrial Design Experts
These experts compare overall visual impressions and individual design elements, assessing whether disputed features are ornamental or functional. They help the court and jury understand how stitching, paneling, seams, and silhouettes influence overall product appearance.
2. Trade Dress Expert Witnesses
Trade dress experts evaluate the distinctiveness and source-identifying features of product design or packaging. They analyze consumer perception, brand recognition, and potential likelihood of confusion, focusing on how a product’s look signals origin.
3. Apparel Manufacturing and Textile Technology Experts
These experts explain garment construction, materials, tolerances, and common industry practices. They clarify when a feature serves performance needs versus appearance, distinguishing functional design from creative expression.
4. Brand Valuation and Financial Experts
Financial experts estimate damages, including lost profits, unjust enrichment, reasonable royalties, and potential brand dilution. They connect alleged infringement to measurable market outcomes and brand equity effects.
5. Intellectual Property Strategy and Trademark Experts
IP strategy experts clarify how trade dress, trademark, and design patent protections interact. They outline enforcement options, address secondary meaning, and help align evidence with the relevant legal standards.
Key Legal Insights and Litigation Considerations in the Lululemon v. Costco Case
1. Functionality vs. Ornamentality
A central question is whether the challenged features are aesthetic (supporting trade dress or design protection) or functional (limiting protection). Design experts and technical documentation often inform this distinction.
2. Establishing Secondary Meaning
To establish trade dress rights in product design, a plaintiff must typically prove that consumers associate the overall look with a single source. Evidence may include advertising, sales success, media coverage, and consumer surveys.
3. Measuring “Dupe” Effects and Consumer Confusion
Social and retail data, consumer surveys, and marketplace context can help assess whether look-alike products cause confusion or influence purchasing decisions.
4. Supply Chain and Retailer Responsibility
When a retailer sells items from multiple vendors, discovery may examine sourcing relationships, design approvals, and vendor warranties to determine accountability for design choices.
5. Integrated IP Enforcement
Coordinating trade dress, trademark, and design patent claims creates a layered strategy for protecting distinctive designs while addressing both source confusion and substantial similarity to patented elements.
Conclusion
The Lululemon v. Costco lawsuit highlights the evolving boundaries of trade dress and design patent protection in the fashion industry.
The decision could help clarify how courts balance creative protection with fair competition when popular apparel designs are widely imitated.
For practitioners, the case underscores the importance of expert-led design analysis, consumer research, and damages modeling in complex fashion IP litigation.
