Rectangular conductors for medium to high voltage motors are covered with polyester-backed mica paper impregnated with a low quantity of epoxy resin. The combination of mica and polyester film provides high breakdown voltage and good elasticity, in combination with good partial discharge, electrical creepage and radiation resistance.  Multiple variations of build and lapping are possible with the use of sophisticated high-speed covering machines, and numerous variations of bonding and non-bonding conductor tape construction are used to suit customer specifications.