To trigger the start of the one-year statutory bar under 35 U.S.C. � 102(b), must an invention be actually reduced to practice or substantially completed when sold or offered for sale? Neither, ruled the Supreme Court in Pfaff v. Wells, 119 S. Ct. 304 (1998). Instead, the invention must be “ready for patenting.”

At issue in Pfaff was the construction of the “on sale” provision of 35 U.S.C. � 102(b), which provides in part: “[a] person shall be entitled to a patent unless . . . (b) the invention was . . . on sale in this country, more than one year prior to the date of the application for patent in the United States . . .” Accordingly, where an invention has been sold or offered for sale in the United States more than one year prior to the filing of the inventor’s patent application, the item offered for sale or sold becomes “prior art” under 35 U.S.C. � 102(b), which may render the subject matter claimed in the patent invalid.