TrafFix Devices v. Marketing Displays — Expired Patent Is Strong Evidence of Functionality in Trade Dress

Background

Marketing Displays, Inc. (MDI) manufactured temporary road signs — the kind you see on highway construction sites warning of lane closures or shoulder work ahead. MDI held two utility patents on the “dual-spring design” used to keep its outdoor signs upright in wind. The design featured two springs attached at the base of the sign stand, positioned to counteract the force of the wind and keep the sign stable. After years of commercial success, MDI’s patents expired.

Once the patents lapsed, competitors including TrafFix Devices began selling sign stands with visibly similar dual-spring bases. MDI sued under the Lanham Act, claiming TrafFix had infringed its trade dress — specifically, the look of the dual-spring mechanism itself. MDI argued it had built up secondary meaning in the design (i.e., consumers had come to associate the look of the springs with MDI as the source), and therefore TrafFix’s copying was actionable even after the patents expired.

The Sixth Circuit sided with MDI, holding that the fact the springs were patented did not automatically doom the trade dress claim. The Supreme Court granted certiorari to clarify the relationship between expired utility patents and trade dress functionality.

The Court’s Holding

Justice Kennedy, writing for a unanimous Court, reversed. The Court held that a prior utility patent disclosing a product feature is “strong evidence” that the feature is functional — and a functional feature cannot receive trade dress protection under the Lanham Act, regardless of any secondary meaning the feature may have acquired.

The Court explained the underlying policy: when a patent expires, the design it claimed enters the public domain. Competitors have an affirmative right to copy it. Allowing trade dress protection to resurrect exclusivity over that same design after the patent expired would frustrate the constitutional bargain that underlies patent law — inventors get a limited monopoly in exchange for public disclosure, and at the end of the patent term the public gets to use the invention freely. Trade dress law cannot be used to extend that monopoly indefinitely.

The Court also clarified the functionality doctrine more broadly: a product feature is functional if it is “essential to the use or purpose of the article” or if it “affects the cost or quality of the article.” Courts need not engage in elaborate balancing once a feature is shown to be functional — the inquiry ends there and the feature is ineligible for trade dress protection, full stop. Secondary meaning is simply irrelevant once functionality is established.

Key Takeaways

• A utility patent covering a product feature creates strong (though not conclusive) evidence that the feature is functional and cannot be protected as trade dress after the patent expires.
• Functional features are categorically excluded from Lanham Act trade dress protection — secondary meaning cannot save a functional feature.
• When a patent expires, competitors acquire the right to copy the patented design; trade dress law cannot be used to extend patent-like exclusivity beyond the patent term.
• Companies seeking long-term protection for product appearance should rely on design patents (limited term) or pursue aesthetic features that are not disclosed in utility patents.

Why It Matters

TrafFix draws a firm boundary between patent law and trademark law. It prevents manufacturers from running a “double dip” — first using a utility patent to establish exclusivity during the patent term, then pivoting to trade dress to maintain that exclusivity forever. The ruling is especially significant for product manufacturers: it means that the look of a useful product feature will rarely (if ever) qualify for trade dress protection when that feature was covered by a utility patent.

The decision also clarified a circuit split over how to analyze functionality, endorsing a straightforward inquiry rather than a multi-factor balancing test. For businesses, it is a practical warning: if you want lasting brand protection for a product’s appearance, design around functional features, and be wary of claiming trade dress in anything you have also sought to patent.