Nowadays, customized optomechanics for complex optical setups are increasingly manufactured additively using the polymer-based process of fused filament fabrication. In this article, a kinematic polymer mirror holder is demonstrated, in which the mirror is imprinted and thus fixed against misalignment. Furthermore, the necessary spring system and ball joint are manufactured in a single printing process. This mirror holder can then be embedded into an also printed cage system. Mirror mounts made of different polymers are examined and compared with each other. The mechanical stress induced into the imprinted optic is determined. Regarding the 3D-printed spring system, the angular alignment range as well as the load limits are defined. The reproducibility of the mirror’s angular position and the long-term stability together with the influence of thermal cycling is determined. The results will be compared with a conventional, subtractive manufactured metallic optomechanic.