Law360, New York (September 4, 2015, 10:21 AM EDT) -- Infringers of a design patent or trade dress can occasionally respond to a charge of infringement by noting that they have obtained a patent for the challenged design (or something close to it), and by arguing that the U.S. Patent and Trademark Office's finding of separate patentability effectively rules out a finding of infringement. As this retort usually goes, the holder of a later-issued patent for the challenged design will incant the oft-quoted language of National Presto Indus. v. West Bend Co., 76 F.3d 1185, 1192 (Fed. Cir. 1996) that "the fact of separate patentability is relevant, and is entitled to due weight" in a determination of whether the design infringes an earlier-issued patent. Upon fielding this one-two punch of fact and law, would-be plaintiffs typically retreat to the ropes and attempt to leave the ring as inconspicuously as possible — hoping to avoid any further embarrassment for their apparent over-aggressiveness....