Lululemon athletica canada inc. (lululemon) and Calvin Klein, Inc. (Calvin Klein) have agreed to settle their patent infringement lawsuit involving the design of yoga pants.

As previously discussed by Arent Fox, on August 13, 2012, lululemon sued Calvin Klein before the U.S. District Court for the District of Delaware for direct and indirect willful infringement of lululemon’s yoga pant design patents. lululemon asserted that Calvin Klein’s sale of certain yoga pants that incorporated similar design elements as those in lululemon’s patents, constituted direct and indirect patent infringement. The terms of the settlement agreement are confidential.

While intellectual property lawsuits in the fashion industry are usually based on trademark or copyright, lululemon’s novel approach of protecting and enforcing its designs through patents could encourage other companies to pursue similar avenues. This case also emphasizes the challenges fashion designers face in protecting their designs. Although trademark, trade dress, and patent law can afford some protection to aspects of fashion designs, the absence of a formal regulatory scheme creates uncertainty with respect to a designer’s ability to enforce and protect designs that they believe are proprietary.