The Supreme Court held 3/20/01 that the Lanham Act’s trade dress protection -- which does not apply to "functional" features of a device -- did not apply to a product feature that was the subject of expired utility patents. Marketing Displays’ patented dual-spring design permitted its road signs to withstand strong wind. When the patents expired, TrafFix Devices began manufacturing road signs using a similiar dual-spring design. Marketing Displays sued under the Lanham Act, claiming that the use of the design infringed its trade dress.A unanimous Court rejected Marketing Displays’ claim, reversing the Sixth Circuit. It held that "[w]here the expired patent claimed the features in question, one who seeks to establish trade dress protection must carry the heavy burden of showing that the feature is not functional, for instance by showing that is merely ornamental, incidental, or arbitrary aspect of the device." Because the dual-spring design was the central advance claimed in the expired patents and was clearly functional in that it was "essential to the use or purpose of the article" or affected "the cost or quality of the article," the Court ruled that Marketing Displays had failed to meet its burden of proof.