a process of manufacturing an insulator having a central core and an insulating body fitted tightly around the central core includes interposing a flexible coating layer between a part of the central core and the insulating body . the flexible coating layer fills in shrinkage cavities and compensates for a retraction effect caused by injected material used in forming the insulating body . the insulating body is achieved by overmolding the central core previously coated with the flexible coating layer with an injected insulating resin such as a thermoplastic or thermosetting resin . the insulator could be used as a capacitive divider or bushing insulator .