This study investigated the impact of 3D printing technology and the feasibility of adopting an alternative material to improve sustainability in the manufacture of a clubfoot brace. An advanced material selection process gave ABS, PLA and PETG materials as the optimum materials for the manufacture of a low-cost stiffness-limited clubfoot brace, using 3D printing technology. However, a cheaper recycled PETG (rPETG) filament material was used in place of the earlier selected PETG to additively manufacture specimens for the mechanical tests. Taguchi design of experiment was adopted in order to link these filament materials together with other 3D printing parameters such as infill percentage and layer height to identify the optimum input parameter combination for flexural, compressive and tensile strength. Test specimens were designed on Creo parametric software as per ASTM standard and 3D printed using parameter combinations designed with the Taguchi technique. Responses for the signal-to-noise ratios of the respective tests revealed that filament material is the most influential parameter, followed by infill percentage for flexural strength and layer height for compressive strength. Main effects plots of the SN ratios identified the rPETG material as the optimum for flexural strength at 13% infill percentage and 0.15 mm layer height. While PLA gave the best compressive strength at parameter combination of 13% infill percentage and 0.10 mm layer height. Results obtained from the grey relational analysis for multi-response optimization revealed that rPETG is the highest-ranking material with a grey relational grade of 0.801.