By Jerry Selinger, Patterson & Sheridan LLP. (May 2, 2017, 5:01 PM EDT) -- United States law has long prohibited the patenting of an invention that was "on sale" in the United States before the inventor filed a patent application, unless that activity fell within a statutory grace period. See, e.g., 35 U.S.C. §102(b)(one-year grace period). In Pfaff v. Wells Electronics Inc., 525 U.S. 25 (1998), the court held Section 102(b)'s on-sale bar is triggered if product is the subject of a commercial offer for sale and the invention is ready for patenting. The ready-for-patenting prong may be shown "by proof of reduction to practice before the critical date; or by proof that prior to the critical date, the inventor had prepared drawings or other descriptions of the invention that were sufficiently specific to enable a person skilled in the art to practice the invention." ...