This work proposes an approach to generate high performance rectangular hollow waveguides for applications in E- and W-Band by stereolithography 3D plastic printing and subsequent copper electroplating. In order to improve the metal deposition process, large and densely positioned sidewall gaps are identified as a key parameter in the design for manufacturing of such transmission lines with the proposed fabrication strategy. Measurements of fabricated prototypes achieve an overall attenuation of about 8 to 10 dB/m over wide bandwidths and thus, perform in similar ranges as compared to conventionally manufactured waveguides. Despite the large sidewall gaps, radiation leakage has been measured in an order of -50 dB, suggesting feasibility to many practical applications. The proposed approach offers fundamental contributions to the design for manufacturing of 3D printed waveguide systems and increases the applicability of conventional electro-plating processes.