Sustainable 3D printing creates products made layer by layer that reduce pollution, save energy, save natural resources, and are economical and safe for workers, communities, and consumers. These aspects can be applied to the sustainable 3D printing process by creating a mathematical model to find optimal sustainable 3D printing process parameters. This study develops a multi-objective optimization mathematical model to find the optimal solution for sustainable 3D printing process parameters by considering quality loss. This study involved several decision variables representing geometric variables: filament diameter, process variables, printing speed, structural variables, number of layers, and layer thickness. This study has three objective functions: minimizing carbon emissions, minimizing waste, and minimizing quality loss. The Gamultiobj algorithm (MATLAB) and the Non-dominated Sorting Genetic Algorithm II method are used to search for optimal values for the four objective functions simultaneously. This study shows that considering the quality loss function, the optimal values align with reality because it considers the variability of quality and potential loss of quality in currency units.