The Supreme Court in Traffix Devices, Inc. v. Marketing Displays, Inc., 121 S. Ct. 1255 (2000) outlined the scope of protection a party may have in the trade dress of an article, where a utility patent has also been obtained for the article. In certain situations, trade dress law can provide protection for a product's appearance. One defense to an allegation of trade dress infringement is that the product's appearance is based on functional considerations, as opposed to ornamental considerations.

In this case, Marketing Display Inc.'s (MDI's) utility patents for a dual-spring mechanism to permit signs to withstand winds had expired. After expiration, Traffix copied the design. MDI argued that its product's design was still protectable under trade dress law, and that it's trade dress was infringed by Traffix.

The Court explained the devastating effect an expired utility patent might have on a claim of trade dress infringement. First, the Court noted that the burden of proving non-functionality was on the party asserting trade dress protection under the Lanham Act at 15 U.S.C. §1125(a)(3). The Court also restated the standard by which the appearance of a product may be deemed unprotectable as functional: when it is "essential to the use or purpose of the article" or "affects the cost or quality of the article." Concluding that a prior patent can have vital significance in resolving a trade dress claim, the court held "[i]f trade dress protection is sought for [allegedly functional] features the strong evidence of functionality based on the previous patent adds great weight to the statutory presumption that features are deemed functional until proved otherwise by the party seeking trade dress protection."

MDI argued the functionality of the springs in the prosecution of its patent and successfully litigated an infringement action against a different company that manufactured dual-spring signs. These actions indicated to the Court that MDI's design provided a unique and useful mechanism to resist the force of the wind. MDI's trade dress claim on the same elements was thus denied as being functional.

The Court, in coming to its conclusion, specifically referenced the fact that inventors often argue the functionality of certain aspects of their inventions during patent prosecution and pointed out that the prosecution file may be fertile ground for finding functionality arguments. This tip should provide guidance to practitioners to thoroughly investigate trade dress claims in the relevant U.S. Patent and Trademark Office records, and hopefully reduce the number of meritless cases filed in the first place.