Conducting varnish is used to damn/suppress corona discharge in high voltage motor. It is brushed over straight portion of the coil.
Zweck Tape / Self fusing silicone tape is the most versatile and multi-use
It consist of fibreglass fabric coated with different temperature class of Varnishes i.e. polyur
Made up of fibres like Glass, Polyester and others. It is available in different types of weaves