How Thermal Mass Changes the Behavior of a Kapton Heater

https://heating-element-insights.westhavenscope.com/posts/pi-heater-design-factors-for-better-temperature-uniformity

In precision instruments, a kapton heater must deliver heat in a controlled way. It uses a resistive foil circuit laminated within polyimide film. One useful trait is custom circuit patterns. Still, hot spots can change the result