In the case of American Net and Twine Company v. Worthington, 1891, the U.S Supreme Court ruled in favor of Worthington. The dispute arose when American Net and Twine Company claimed that they had a patent for an improvement to fishing nets which was infringed upon by Worthington's product. However, it was found that their alleged invention did not involve any new principle or mode of operation but merely substituted one material for another without producing a different result or function than what existed before in previous patents. Therefore, it could not be considered as an invention under patent law standards at that time. Furthermore, even if there were novelty involved in using cotton twine instead of linen thread (as used previously), this would have been obvious to anyone skilled in the art and thus unpatentable due to lack of inventive step.

The dissenting opinion in the case of American Net and Twine Company v. Worthington argued that the majority's decision to uphold a patent for an improvement on a fishing net machine was incorrect. The dissent believed that the supposed 'improvement' did not meet the standard of novelty required for patent protection, as it merely involved using old methods in slightly different ways without introducing any new principles or mechanisms. They contended that such minor modifications should not be enough to warrant a new patent, as this would undermine competition by allowing companies to monopolize basic techniques through continual slight alterations. Furthermore, they expressed concern about potential abuse of the patent system if such low standards were accepted.