The recent fast development of terahertz technology finds applications in many technological aspects used in security, medicine, biology, telecommunication, astronomy, and many others. Each of them requires individual optical components made of well-performing materials adapted to the particular application. This work examines the optical properties of different polymer materials used in 3D printing techniques examined and verified by the terahertz time-domain spectroscopy. Moreover, composite materials significantly influence on polymer base optical and mechanical performance.