Conducting varnish is used to damn/suppress corona discharge in high voltage motor. It is brushed over straight portion of the coil.
High Voltage 4323 self amalgamating tape based on EPR ( Ethylene Polypropylene Rubber).
Zweck Tape&trade / Self fusing silicone tape is the most versatile and multi-use non-stick
It consist of fibreglass fabric coated with different temperature class of Varnishes i.e. polyur