Thin Wire Coating

I don't know what kind of wire is that (tapered, so conical from o.d. 0.012" to 0.002" ?).

Difficult job.

You must find a die of 0.013". Find a PTFE varnish ?? (???? God! Don't know) (why PTFE or Nylon? They are prety different. Nylon does not resist heat or chemicals, but PTFE does. Good electric properties could have many others polymers Isn't a polyester or a poliesterimide good enough ? Epoxy ? You could find a varnish for each of these (you have to dilute it, the diameter is very small). Cure after dieing.

Interesting. Maybe if you can let others know the final use of the coated wire ;it will be easier to discuss.

What tolerance do you need?

Multiple drawings and/or variable drawing rate of the wire from a bath, followed by curing, can do this sort of thing - but it's not trivial. If you only need to make a few, would it be worth depositing a thicker coating and then cooling the wire so that you can machine it to size?