Plastics play an important part in electrical instruments and installations as insulating and constructional materials where they offer both technical and economic advantages. New developments in electrical engineering are often connected with increased demands on plastics. The author discusses the resultant progress in the use of plastics, using examples of recent or improved plastics applications which have become established in practice. These demonstrate that plastics and the electrical industry complement each other to the best advantage in the development and application of modern synthetic materials and progressive processing techniques.