The Dupe Dilemma: When Flattery Becomes Infringement, and What Brand Owners Should Do About It

When flattery files in federal court

Imitation may be the sincerest form of flattery, but it is rarely the most profitable. Ask Mondelēz International, whose trade dress complaint against Aldi, filed on 27 May 2025 in the Northern District of Illinois, reads like a forensic autopsy of snack-aisle déjà vu. Ask J.M. Smucker, which on 13 October 2025 sued Trader Joe’s in the Northern District of Ohio over a rival crustless peanut butter and jelly sandwich. Ask Lululemon, whose 27 June 2025 complaint against Costco in the Central District of California reads like a side-by-side gallery of athleticwear lookalikes sold under the Kirkland Signature label. Or ask Pacific Market International, which on 6 November 2025 sued Five Below in the Northern District of California over discount tumblers accused of duping the viral Stanley Quencher and IceFlow lines.

These cases may differ in industry, geography, and doctrinal emphasis, but they share a single animating question: how close can a “dupe” come to the genuine article before it crosses from lawful competition into actionable infringement? For in-house counsel advising brand owners, the answer is no longer academic.

The dupe economy, once a fringe subculture of viral hashtags and influencer side-by-sides, has matured into a structural challenge to the economic foundation of premium brands, and the doctrinal architecture for responding is undergoing its most meaningful recalibration in a generation.

What is a dupe, legally speaking?

A “dupe”, short for “duplicate”, is consumer shorthand for a product engineered to resemble a more expensive original at a fraction of the price, without carrying the original’s name or logo. Unlike the classic counterfeit, which forges a brand’s mark, the dupe is typically honest about what it is. It says, in effect, “this isn’t the real thing, but it looks close enough”. That honesty is both the dupe’s commercial strength and the brand owner’s litigation problem.

The dupe tests every seam of the United States IP system. It is not quite a trade mark counterfeit, because it disclaims the original’s mark. It is not quite a plain copy, because US law permits a great deal of lawful imitation of unprotected features. It sits, often deliberately, in the narrow space where trade dress, copyright, and design patent protection overlap, and where each regime, on its own, has recognised weaknesses. Understanding why requires a tour of all three.

The current docket: four cases worth watching

Mondelēz v Aldi

Mondelēz’s complaint alleges that Aldi’s Benton’s and Savoritz house brands copy the trade dress of seven iconic snack packages: Oreo, Chips Ahoy!, Nutter Butter, Nilla Wafers, Wheat Thins, Ritz, and Premium Saltines. The grievance is not the underlying cookie; it is the blue package with a tilted Oreo, the red-and-gold Ritz geometry, the peanut-shaped Nutter Butter silhouette. According to the complaint, Aldi had previously agreed to discontinue or redesign flagged products, yet allegedly resumed the conduct across multiple SKUs. Mondelēz pleads wilful trade mark and trade dress infringement, unfair competition, unjust enrichment, and federal and state dilution, and seeks injunctive relief and treble damages.

The case is a textbook packaging trade dress dispute. If litigated to judgment, it will test how robust the secondary meaning of legacy consumer brands truly is under modern survey methodology, and whether Aldi’s “Like Brands, Only Cheaper” tagline cuts against consumer confusion, by signalling the non-brand status openly, or reinforces Mondelēz’s dilution theory by demonstrating intentional trade-off.

J.M. Smucker v Trader Joe’s

Smucker alleges that Trader Joe’s Crustless Peanut Butter & Strawberry Jam Sandwiches copy the round shape, crimped edges, and blue packaging of the Uncrustables line, a brand Smucker says is on course to reach one billion dollars in annual sales. The complaint leans on federal trade mark registrations covering the circular, sealed-edge sandwich configuration and the “bite-taken-out” image on the packaging.

The vulnerability is immediately visible to any trade dress practitioner: functionality. A round sealed sandwich is round and sealed because those features keep the filling in, the crust out, and the product stackable. Smucker will need to convince the court that its particular round-and-crimped presentation has acquired distinctiveness as a source identifier, not merely as an efficient way to contain jelly. Academic commentators have already expressed scepticism on precisely that point.

Lululemon v Costco

Lululemon’s complaint targets Costco’s Kirkland Signature and affiliated apparel, alleging that six garment designs, including versions of the Scuba hoodie, Define zip-up jacket, and men’s ABC pant, infringe Lululemon’s trade dress and design patents, and that Costco’s use of the colour “Tidewater Teal” compounds the mimicry. The complaint weaves in a clever source-confusion theory built on Costco’s use of shared manufacturers: consumers, the argument goes, may reasonably believe Kirkland items come from the same factory floor as the originals.

Lululemon’s case is doctrinally richer than the snack disputes because it pleads design patent claims alongside trade dress. That matters enormously after the Federal Circuit’s May 2024 decision in LKQ v GM (discussed below). The case also sits squarely in the Ninth Circuit, a jurisdiction whose trade dress jurisprudence is central to any brand owner with meaningful West Coast sales, and to any Arizona-based business litigating in its home circuit.

PMI Worldwide v Five Below

Pacific Market International, the maker of the viral pop-culture Stanley Quencher and IceFlow tumblers, filed suit against Five Below in the Northern District of California on 06 November 2025, alleging that Five Below’s Hyperquench, Hydraquench, HydraSip, and Hydrachug drinkware infringe its design patents, trade dress, and trade marks. The complaint asserts, among others, U.S. Des. Patent No. D805,838 (tumbler lid) and U.S. Des. Patent No. D955,173 (beverage container), and pleads trade dress rights in the Quencher’s squared-off handle, the metal band between cup and lid, and the strip at the top of the lid. PMI accuses Five Below of “parasitic and intentional copying” and alleges wilfulness based on Five Below’s continued sales after receipt of a cease-and-desist letter. The case is Pacific Market International, LLC v Five Below, Inc., No. 3:25-cv-09604 (N.D. Cal.).

PMI is doctrinally the most interesting of the four pending cases because it engages all three pillars this article discusses – trade dress, design patents, and trade mark – in a single complaint filed squarely in the Ninth Circuit. Five Below’s answer and counterclaims, filed on 2 January 2026, telegraph precisely the defences every brand owner should anticipate. The asserted trade dress features (handle shape, metal banding, lid geometry) are alleged to be functional and commonplace across the tumbler market; the asserted design patents are alleged to be invalid as covering utilitarian features in a crowded art; and Five Below seeks declaratory judgment of invalidity, unenforceability, and non-infringement.

For any consumer-goods brand owner whose IP strategy depends on enforcing trade dress and design patents simultaneously, PMI v Five Below is the case to watch. Its rulings on the functionality of common drinkware features, and its post-LKQ treatment of design patent validity, will ripple across the Ninth Circuit and beyond.

The three pillars of protection (and where each one cracks)

Pillar one: trade dress

Trade dress protects the total visual impression of a product or its packaging – its “look and feel”. Lanham Act § 43(a), 15 U.S.C. § 1125(a), provides a federal cause of action, and Two Pesos, Inc. v Taco Cabana, Inc., 505 U.S. 763 (1992) confirmed that inherently distinctive trade dress is protectable without proof of secondary meaning.

The complications arrived shortly after. Wal-Mart Stores, Inc. v Samara Bros., Inc., 529 U.S. 205 (2000) held that product design trade dress, as distinct from packaging, is never inherently distinctive and always requires proof of secondary meaning. That is a substantial evidentiary burden typically met only with surveys, long exclusive use, and heavy advertising expenditure. And TrafFix Devices, Inc. v Marketing Displays, Inc., 532 U.S. 23 (2001) established that functional features are categorically unprotectable as trade dress, regardless of how distinctive they may appear.

Together, these doctrines mean a brand owner asserting trade dress faces three sequential hurdles: establishing that the claimed dress is non-functional; establishing distinctiveness (inherent for packaging, secondary meaning for product design); and establishing likelihood of confusion, which in the Ninth Circuit is governed by the eight Sleekcraft factors from AMF Inc. v Sleekcraft Boats, 599 F.2d 341 (9th Cir. 1979).

Where the doctrine cuts against brand owners

The functionality doctrine is brutal and, in the Ninth Circuit, well-developed. Any feature that is essential to the use or purpose of the article, or affects cost or quality, is functional. A round sandwich is functional. A zippered hoodie collar is functional. A blue background may be “aesthetically functional” if blue is the industry’s colour code for a given product category. Brand owners who treat trade dress as a standalone shield will frequently find it has already leaked.

Pillar two: copyright

Copyright protects original works of authorship fixed in a tangible medium of expression. For dupe litigation, the relevant doctrine lives in a narrow corner of copyright law: the protection of design elements in useful articles – ie, clothing, packaging, product shapes, under the separability test refined in Star Athletica, L.L.C. v Varsity Brands, Inc., 580 U.S. 405 (2017).

Star Athletica held that a design element on a useful article is copyrightable if it can be perceived as a two- or three-dimensional work of art separate from the article, and would qualify as a protectable pictorial, graphic, or sculptural work if imagined apart from it. The decision was heralded as a win for fashion and product designers, but its practical reach has been narrower than the headlines suggested.

The separability test protects surface decoration, such as stripes, chevrons, prints, graphic patterns, far more readily than it protects silhouettes, cuts, or structural features. A Lululemon jacket’s decorative quilting pattern may be copyrightable; its raglan sleeve construction almost certainly is not. Packaging artwork like the Oreo swirl or the Ritz red crown graphic is more squarely within copyright’s comfort zone.

Where the doctrine cuts against brand owners

Copyright registration is inexpensive, swift, and routinely overlooked. Many brand owners fail to register the artwork on their packaging or the graphic elements on their products, foreclosing the statutory damages, up to USD150,000 per work for wilful infringement under 17 U.S.C. § 504(c)(2), and attorneys’ fees that make copyright litigation economically viable. The functionality exclusion also bites: anything that shapes the product rather than decorates it is typically outside copyright’s scope.

Pillar three: design patents

A design patent, granted under 35 U.S.C. § 171, protects the new, original, and ornamental design of an article of manufacture for 15 years from issuance. It is the one IP right that protects the shape itself of a product – eg, the silhouette of a bottle, the contour of a running shoe, or the profile of a chair.

Design patents have long been the quiet workhorse of strategic IP portfolios, and for a period between Apple v Samsung and mid-2024 they were regarded as relatively easy to obtain and formidable to enforce. That changed on 21 May 2024 when the Federal Circuit, sitting en banc, decided LKQ Corp. v GM Global Technology Operations LLC, 102 F.4th 1280 (Fed. Cir. 2024). LKQ abandoned the decades-old Rosen-Durling two-part test for design patent obviousness and replaced it with a flexible Graham-factor analysis borrowed from utility patent law, drawing explicitly on KSR International Co. v Teleflex Inc., 550 U.S. 398 (2007). The consequence: design patents are harder to obtain and easier to invalidate than they were under the prior regime. Prior art combinations that would previously have been dismissed under Rosen-Durling’s rigid “basically the same” threshold are now fair game in both prosecution and post-grant challenges.

Where the doctrine cuts against brand owners

LKQ is a mixed blessing for dupe litigation. Design patents remain uniquely powerful; they require no proof of secondary meaning and no proof of consumer confusion, only that the accused design would appear substantially the same to an ordinary observer under Gorham Co. v White, 81 U.S. 511 (1871). But LKQ means design patent portfolios now require more careful prosecution, more defensible prior art records, and earlier filing discipline. The old practice of filing a single design patent and hoping for the best is no longer tenable.

The Ninth Circuit angle: why it matters even when the case is filed elsewhere

Of the four cases above, two – Lululemon v Costco and PMI v Five Below – are pending in the Ninth Circuit’s domain. That alone is instructive: the most doctrinally ambitious dupe cases of the current docket, the ones pleading trade dress and design patents together, are both in Circuit courts whose decisions Arizona-based brand owners (and any consumer-goods company with meaningful West Coast distribution) should treat as the operating manual.

Three points matter most:

• First, the functionality analysis is rigorous: the Circuit applies Disc Golf Association, Inc. v Champion Discs, Inc., 158 F.3d 1002 (9th Cir. 1998), which asks whether the feature is essential to use, affects cost or quality, or has commercially viable alternatives. Brand owners should document the availability of alternative designs at the time of their design choices, not after the dupe appears.
• Second, theSleekcraft factors govern likelihood of confusion: eight factors, fact-intensive, and heavily survey-dependent. Investing in confusion surveys at the pre-litigation stage is often worth the cost.
• Third, Ninth Circuit apparel and consumer-goods cases lean fact-specific. The Circuit’s decision in adidas America, Inc. v Skechers USA, Inc., 890 F.3d 747 (9th Cir. 2018) illustrates how trade dress can protect a distinctive product silhouette while simultaneously denying protection to other elements the plaintiff wanted to claim. The lesson: plead specifically, prove specifically.

Where the dupe economy pushes back

Candor is useful here. In-house counsel who walk into mediation without having internalised the defences will leave leverage on the table. Four counterarguments are effectively certain to appear in any dupe dispute.

• “No one is confused”. TikTok’s #LululemonDupe hashtag is now a litigation exhibit. Defendants argue that a thriving dupe culture, in which consumers proudly and openly seek out the lookalike because it is a lookalike, negates the likelihood of confusion. The argument is not frivolous, though brand owners can respond with post-sale confusion theories, sponsorship-or-affiliation confusion, and the observation that dupe culture itself presupposes the distinctiveness of the original.
• “The features are functional”. This is the single most important defence in dupe cases. Brand owners should anticipate it in every consultation, every clearance, and every filing. A product design that evolved for engineering reasons will struggle to be repositioned as trade dress after the fact.
• “The trade dress lacks secondary meaning”. This is especially acute in product-design cases after Wal-Mart v Samara Bros. Brand owners must be prepared with survey evidence, advertising expenditure records, unsolicited media coverage, and documented consumer associations, ideally compiled before a dispute arises.
• “The design patent is obvious under LKQ”. Expect aggressive inter partes review (IPR) filings. Design patent portfolios built under the old Rosen-Durling regime deserve a fresh review under the new framework, including assessment of whether continuation strategies might shore up vulnerable claims.

A layered strategy: why no single pillar is enough

The through-line of the preceding analysis is that no single IP right is sufficient against a sophisticated duper. Trade dress is vulnerable to functionality defences. Copyright protects decoration but not structure. Design patents, post-LKQ, require more investment and survive less easily. The answer is layered protection: the deliberate, contemporaneous deployment of all three regimes against the features most worth defending.

A layered strategy works because duplication that evades one regime often infringes another. A competitor who drafts around a design patent may still copy protected packaging artwork. A competitor who changes the artwork may still misappropriate protectable trade dress. Layering multiplies the defendant’s cost of designing around, and it increases the plaintiff’s leverage at every stage from demand letter to trial. It also creates rhetorical cohesion: a complaint that pleads trade dress, copyright, and design patent together tells a story of deliberate, systematic copying that any one claim alone would struggle to convey.

The lesson of the current docket is that the brand owners bringing the most formidable cases – ie, Lululemon most clearly, are those who invested in layered portfolios before anyone started calling their products “dupes”. The brand owners most exposed are those who relied on a single right, typically trade dress, and are now discovering its limits in public.

A practical checklist for in-house counsel

The following is a condensed action list for legal teams at brand-owning enterprises. It is not exhaustive. It is what every in-house IP counsel should have either already done or already scheduled:

• Conduct a trade dress audit. Identify which packaging and product designs are genuinely non-functional, distinctive, and associated with your brand. Document secondary-meaning evidence now – eg, advertising spend, unsolicited media, and survey data, while it is still cheap to obtain.
• Register the copyright in your packaging artwork. The filing fee is nominal. The upside – statutory damages and attorney’s fees under 17 U.S.C. § 505 – is outsized. This is the most frequently neglected step in consumer-goods IP strategy.
• File design patents early and often. A design patent application must be on file before, or within a narrow grace period after, public disclosure. Treat every meaningful product launch as a filing opportunity. Post-LKQ, prosecution should emphasise careful claim drafting and thorough prior art review.
• Build a marketplace surveillance programme. Monitor retailer house brands, Amazon marketplace listings, TikTok Shop, and fast-fashion platforms. Trade mark and trade dress rights can be weakened by tolerated infringement; documented enforcement preserves them.
• Draft a demand-letter playbook. Many dupes are withdrawn on first contact. A standardised, escalation-tiered demand process reduces enforcement cost and creates the paper trail that matters if litigation becomes necessary.
• Re-evaluate pre-LKQ design patents. Portfolios prosecuted under the Rosen-Durling framework may have vulnerabilities under the new standard. Continuation and selective reissue strategies may help shore up claims that matter most.
• Co-ordinate across IP regimes. Trade dress counsel, copyright counsel, and patent prosecutors often work in separate silos. Force them into the same room at least once per product cycle. The dupe economy does not respect doctrinal boundaries; neither should the defence.

The road ahead

The cases currently pending, Mondelēz v Aldi, Smucker v Trader Joe’s, Lululemon v Costco, and PMI v Five Below, will not all succeed. Some may settle on confidential terms that teach the bar nothing. Some may produce rulings that clarify functionality doctrine, secondary-meaning standards, or post-LKQ design patent enforceability. All four, however, signal the same strategic reality: brand owners are no longer willing to treat dupe culture as the cost of doing business, and they have begun to invest in the doctrinal infrastructure necessary to push back.

For in-house counsel and the brand-owning enterprises they advise, the question is not whether dupes will arrive. They are already in the aisle, on the feed, and in the cart. The question is whether the brand’s IP portfolio is ready for the fight. The brands that win will be those that built the portfolio before they needed it.