Lepto, a spin-off from the Swiss Federal Laboratories for Materials Science and Technology (Empa), has developed a new process for manufacturing terahertz filters using 3D printing technology. Its core products are metal-polymer filters and polarizers with a thickness of only about 1 micrometer. As terahertz wavelengths range from 0.3 to 3 mm, straddling the boundary between optics and electronics, these components hold potential for applications in satellite communications, astrophysics, 6G research, medical imaging, and even security technology. For critical integration, Lepto uses 3D printing to produce custom frames on demand, creating lightweight, precisely matched carrier structures to ensure these sensitive films can be adapted to different laboratory equipment, measuring instruments, or space systems. This breakthrough is expected to advance terahertz technology in next-generation communications, security imaging, and spectroscopy.