Chapter 7 describes how 3D printing technology will disrupt trademark law’s core function of indicating the source or origin of manufactured goods. The technology dissociates product design from product manufacturing. Design is embodied in a 3D printable file, while manufacturing is commoditized and democratized. When 3D printable files, as opposed to manufactured goods, are offered for sale, symbols appearing “inside” of the digital files (i.e., on the digital object) do not indicate the source of the file. Rather, source indicators are found “outside” of the file, on the websites that offer the files for sale. 3D printing technology will also radically disrupt the doctrine of post-sale confusion. At the same time, current, expanded theories of trademark law condemn uses of symbols that might dilute a trademark or suggest a connection to a trademark owner. These stronger versions of trademark protection, which are widely criticized, would give trademark owners to the right to control most uses of their marks “inside” of files. This would inhibit innovation and creative expression without a clear benefit to the public. Therefore, I recommend against these stronger protections for DMFs.