What is polyamide tape?

i posted / hijacked on another post, but was ignored, all my own fault really:)

relating to glass on top of wonky heater beds! :slight_smile:

hi forgive my ignorance.
the hairspray gives the surface a sticky surface?
what does the polyamide tape do, and how would one use it?,
is it double sided stick, or does the molten filament stick to the metal surface of the tape better than the glass?

many thanks,