Gareth Magennis wrote:

This is a bit weird.

I have an audio power amplifier that uses what looks like strips of pink
silicone sheet between the output transistors and the heatsink.
Hmmm, I've seen these pink ones in old power supplies and such, many years
ago. I haven't seen them in anything recent. Some of the Bergquist pads
have some kind of fabric in them that makes them quite robust.

They also have some Gap-Pad material that is designed to be very squishy.
It is not designed to provide electrical insulation, but to accomodate
uneven parts that have to conduct heat to a heat sink.

Jon