Electroluminescent panels Answered

Greetings,

Anyone have any idea how electroluminescent (EL) panels are made?

I see in this video
https://www.instructables.com/id/Make-your-own-EL-wire-at-home/
that EL wire has a wire wrapped around another one, but what about EL panels.  They don't have wire wrapped around a sheet of copper, do they?

Thanks