[Amps] Mounting noninductive resistor

[Vic Rosenthal]

I am putting together the grid circuit for my ab1 4cx1000a amplifier. I am about to mount a Caddock 100 watt resistor on its heatsink, and I notice what looks like a square of tape on the mating surface of the resistor. Either this is some kind of thermal pad itself or it covers one. Should this 'tape' be peeled off before mounting or left alone?

Vic k2vco