Lexmark International, Inc. (Lexmark) (plaintiff), manufactured and sold printers and toner cartridges. Lexmark sold two types of toner cartridges for use in Lexmark’s printers: regular and Return-Program. Purchasers could refill and reuse regular cartridges. Customers could purchase Return-Program cartridges at a 20-percent discount but had to return the cartridges to Lexmark after a single use. Impression Products, Inc. (Impression) (defendant), acquired and refilled used Return-Program cartridges. Impression then resold the used Return-Program cartridges to users of Lexmark printers. Lexmark sued Impression for patent infringement, arguing that Lexmark sold the Return-Program cartridges with a clear restriction on their reuse. Impression argued that because of the patent-exhaustion doctrine, Lexmark’s single-use restriction on its Return-Program cartridges was invalid. In support of that position, Impression argued that Mallinckrodt v. Medipart, 976 F.2d 700 (1992), which held that a patentee’s single-use restrictions on the postsale use of a product were valid, was no longer good law. The district court agreed and dismissed Lexmark’s infringement claim. The United States Court of Appeals for the Federal Circuit reversed, relying on Mallinckrodt. The United States Supreme Court granted certiorari.