Sunmark, Inc. (Sunmark) (plaintiff) made SweeTARTS candies and owned the registered trademark “SweeTARTS.” Ocean Spray Cranberries, Inc. (Ocean Spray) (defendant) produced sweetened cranberry juice. In multiple advertising campaigns, Ocean Spray described its cranberry drinks as “sweet-tart” because the drinks had both sweet and tart flavors. Sunmark sued Ocean Spray for trademark infringement and sought a preliminary injunction to stop Ocean Spray from using “sweet-tart” in its advertising. The district court denied the preliminary injunction, finding that Sunmark had failed to show a likelihood of success on the merits. The district court reasoned that Ocean Spray’s use of “sweet-tart” was descriptive, giving Ocean Spray a fair-use defense to allegations of infringement. Sunmark appealed.