30 printing is contributing to a global trend toward customisation, user innovation and democratisation of design and manufacture. A key element of 30 printing is that computer-aided design (CAD) hies are used to instruct printers to create physical 3D products. This article explores patent liability tor creators of CAD files that provide directions for the creation of potentially infringing products. This analysis compares the Australian position to that 11 the US and UK. One US commentator has suggested that 30 printing wil1 leave patentees helpless to combat widespread infringement. By examining primary and secondary infringement case law, this article finds that Australian law creates relatively clear liability for the creation and distribution of CAD files.