From someone coming from electronic engineering not skilled in chemistry,
There are transparent electric conductors in form of ITO ( Indium tin oxide ) coated glass or transparent PET films ( Polyethylene terephthalate ). By etching the ITO coating we can create transparent circuit boards and with the case of ITO coated PET also flexible transparent circuit boards.
There seems to be very little info on what can be used for etching ITO PET sheets. For ITO coated glass, people use HCL with no issue, but will HCL also work to etch ITO but leave the transparent PET film intact, or do PET and HCL react?