While there has been very little change in the conductor materials and overall construction of cables, there has been a significant change in the materials used for insulation and the related processing methods. Companies that failed to adopt the newer materials technologies and processing have been overtaken by those with a clearer vision of future market requirements. We have tried to show that electrical-insulation materials continue to be a key element in the cable industry. We firmly believe that, with the introduction of newer materials such as nanocomposites [10], changes in the next 50 years will be just as dramatic.