Illinois Tool Works Inc. v. Independent Ink, Inc., 547 U.S. 28 (2006), was a case decided by the Supreme Court of the United States involving the application of U.S. antitrust law to "tying" arrangements of patented products. The Court ruled unanimously that there is not a presumption of market power under the Sherman Antitrust Act when the sale of a patented product is conditioned on the sale of a second product in a tying arrangement. A plaintiff alleging an antitrust violation must instead establish the defendant's market power in the patented product through evidence.
Independent Ink was a distributor of printer ink and related products. Trident manufactured ink-related products used in printers used to print bar codes on cardboard. Trident's license, when licensing its printing apparatus to those printers' manufacturers, required them to use Trident ink. However, it did not require end users of the bar-code printers to refill the printers with Trident ink cartridges. Trident did not, though, warranty its printer for use with others' ink cartridges.
In the course of a patent-infringement suit, Independent Ink alleged that Trident's license constituted a tying arrangement in