The status of design under intellectual property law is unresolved in a number of ways; for more than three centuries design has vacillated in between legal categories. Notably, many current problems in the protection of intellectual property in design were already apparent by the mid-nineteenth century. Thus, in the first part of this article, the origins of and legal responses to problems that still complicate design-related intellectual property law are traced. The specific focus is on British law, which was a forerunner for other national laws on design protection. The second part of the article concentrates on Danish law and on the PH lamp, created in the 1920s by the Danish designer Poul Henningsen. An ‘intellectual property biography’ of the PH lamp serves to illustrate the unstable status of design under intellectual property law. Poul Henningsen relied on patent law as well as copyright law for protection against rivals. Hence the lamp has been defined, respectively, as both ‘industrial property’ and ‘artistic property’; as an invention and as a work of art. The twofold character of the lamp in law may be linked to an unresolved relationship, in modern design in particular, between aesthetics and utility.