My '66 was tape. When I repainted it, I just about screwed it up royally. I got in a rush and on the drivers door, I had the stripe painted on and cleared over already and it was in an arch by 1/8" in the middle. Doesn't sound like much, but when you stood back and looked at it, it was a disaster!
I had to correct it before I shot my clear again.
I guess what I'm saying is, don't trust your eyes. I cannot judge a straight line up close now that I wear glasses. Use a straight edge to check your masking if you decide to paint it on.
1966 GT Fastback, restoration almost there! Code T Red with White LeMans stripes.
2015 GT Fastback - Deep Impact Blue