<p>This research study presents the integration of additively manufactured patterns into metal casting in a Lost-polylactic acid (PLA)-inspired process. In this research, the pattern fabricated with Material Extrusion (MEX) technology is not burnt out before the pour but rather disintegrates as it interacts with the molten metal. The research investigation focused on the parameters of pattern shell thickness, coating types, and sand grain size. The pattern material used is PLA, and the cast metal is aluminum alloy. A full factorial Design of Experiment (DOE) was performed to systematically assess the effects of the process parameters like wall thickness, refractory coating type, and sand grain size, noting that the white coating is based on Foam Koat 8025 aluminosilicate refractory with a silica binder, while the blue coating consists of a zircon-based refractory with an organic binder system. To measure the quality of the cast parts, surface roughness, dimensional accuracy, and surface hardness values were tested. Preliminary results indicated that the cast specimens with finer sand and white coating exhibited better hardness and surface finish quality. Three-way analysis of variance (ANOVA) plots in statistical analysis revealed how input parameters affect the quality of cast samples. Further study in optical microscopy (OM), and X-ray radiographic testing was performed to identify the internal casting defects. The findings of this research contribute to the development of robust parameter-selection strategies for achieving good quality and defect-minimized casting outcomes.</p>