Sign Tape?

[Terry01]

They call it fine line tape. Most automotive paint supply shops sell it. Plenty available online too.

 

[Mr. Signboy]

Bron Tapes has a pretty good selection, might call them and explain what you need. I’ve found some pretty unique stuff there in the past.

 

[Dubb Wheeler]

I have tried every tape sold and for 30 years have always used scotch clear tape. (like you wrap gifts with) it is much thinner which gives you a better and crisper edge. it is also cheaper. Fold it over itself at the end for a handle to remove. It don't bend well but does fine for arched letters.