Trademarks are often brand names or logos. Yet other marks involve the overall appearance of a product or business — a concept called “trade dress.” Courts and scholars have long struggled with how to determine whether trade dress is distinctive enough to function as a legally protectable trademark. In attempting to clarify this murky area, Justice Scalia articulated three types of trade dress in Wal-Mart Stores, Inc. v. Samara Brothers, Inc. These include (i) product packaging (e.g., a candy wrapper) and (ii) product design (e.g., an iPhone’s unique shape). The trouble lies in understanding the third category — what Scalia referred to as (iii) “some tertium quid” (e.g., a restaurant’s décor). Under the Supreme Court’s framework, product packaging is eligible for instant protection based on inherent distinctiveness because its “very purpose” is to identify a brand. Product design, though, must first acquire market recognition (i.e., secondary meaning) to be protectable since it usually serves goals unrelated to brand identification. However, the undefined tertium quid is considered capable of instant protection because it is thought to be, as Scalia believed, “akin to product packaging.”

In challenging this prevailing perspective, this Article seeks to demystify tertium quid trade dress. Seldom used in a legal context, tertium quid is an obscure Latin term meaning “third thing” that is associated with the arcane practice of alchemy, where alchemists would mix two inputs to try and produce gold (the third thing). The esoteric tertium quid label conceals this category’s true nature as consisting of what this Article labels “service dress” — trade dress for intangible services rather than tangible products. In recognizing the product/service distinction, this Article looks to the field of service design for legal insights. The service design literature casts serious doubt on whether service dress should be eligible for trademark protection absent secondary meaning. This is because service design, like product design, is usually intended to serve purposes other than brand identification. Moreover, requiring secondary meaning for service dress protection would support fair competition, providing for reasonable limits on the commercial appropriation of both physical and digital environments.