<p>This study presents a comprehensive analysis of the mechanical and microstructural behavior of components manufactured using material extrusion (MEX), specifically for virgin and polymer-infused materials with multi-walled carbon nanotubes (MWCNT). The investigation focuses on both pre- and post-processing technologies, which include annealing, vapor smoothing, and epoxy layer adhesion. This analysis helps to investigate mechanical characterization, such as tensile strength and microstructure behavior, including agglomeration and dispersion. Firstly, post-processing technology annealing is carried out to reduce inherent stresses and enhance crystallinity properties. Secondly, vapor smoothing is used to minimize surface roughness properties and improve the overall aesthetics of the printed parts. Lastly, epoxy layer adhesion is carried out, which greatly influences the surface roughness and aesthetic behavior of printed parts. Mechanical testing is conducted on the printed samples with different post-processing parameters to investigate the impact of nanoparticle dispersion and agglomeration. The tensile strength results show an improvement in the strength up to 5–7% for PLACNT and 6–9% for PETGCNT. Microstructural investigation of pre- and post-processing parameters displayed changes induced by processing parameters, showing the agglomeration percentage improved from 37 to 67% in PLACNT and 32 to 57% in PETG CNT. This research provides deeper insights into the interaction between MEX process parameters and nanomaterial-infused polymers. Overall, the study enabled the development of high-quality 3D printed components with improved dimensional accuracy and mechanical integrity, suitable for advanced applications in aerospace, robotics, and structural systems.</p>