To show copyright infringement, the plaintiff must show the infringing item was copied from the original. The copyrighted artistic expression must either have no substantial practical utility (e.g. a statue) or be separable from the useful substrate (e.g. picture on a coffee mug).

Design patents, on the other hand, protect the ornamental aspects of an article of manufacture from being infringed. One does not have to show that the infringing item was copied from the original. Thus a design that was arrived at independently can still infringe