Multi-layered blown film extrusion has demonstrated strong capability for diversified product range and production throughput in industry. There, however, exists a performance chasm between a monolithic layer and multi-layer film of the same thickness and material. The thickness of the layers and the total film thickness can be estimated from the scanning electron microscopic images. Layer multiplicity in blown film herein demonstrates improved mechanical performance and reduction in oxygen permeation. Maintaining similar thickness, a five-layer nylon film exhibits approximately 20% reduction in oxygen permeation. A significant improvement in stiffness and load at yield can be achieved during tensile stretching in both machine and transverse direction. This improvement may allow for better performing product or efficient process through down gauging. The rationale for this is presented based on detailed investigation on the interfacial morphology.