Manufacturing methods related to anodizing of metal parts are described. In particular, pre-anodizing and post-anodizing methods for forming a consistent and defect-free interface between metal and non-metal sections of a part are described. Methods involve preventing residues from various manufacturing processes from entering a gap or space at the interface between the metal and non-metal section of the part and that can disrupt subsequent anodizing and anodic film dyeing processes. In particular embodiments, methods involve forming a barrier layer or filler layer between the metal and non-metal sections. Portions of the barrier layer or filler layer can be removed prior to anodizing. The resultant part has a well-defined and uniform space between the metal and non-metal sections that is free from visual defects.