True scale, on even as large as 1/4 scale, would be nothing more than what you would get by scoring the panel lines with a sharp knife. Since, as modelers, we are trying to represent a visual facsimile' at a smaller scale than 1:1 the 1/32 works just fine and is easier to use than fighting with the 1/64. the smaller tape winds up breaking repeatedly when trying to remove after sanding and gets to be quite tedious picking at the snapped ends with a pointy knife to get a bit to grip in order to continue removal. then you get numerous little gouges in many of your lines. Again, because we are modeling, we tend to wantto bring to attention some of the subtlties that wouldn't be readily apparent on 1:1. with that in mind and due to the tedium involved with the smaller tape I tend toward the 1/32.

Try a test panel...get a piece of 2x4 about 2 ft long and give it a few coats of primer and sand to get rid of the wood grain(or go ahead and glass it) then do a few lines of each all the way through color and clear coat and judge for yourself. Wouldn't take any time at all relative to what your'e going to spend on your plane and you'll get a good representation of what each will look like and the difference in dealing wth the two as well.

Real 1:1 wing and a model 1:7.5 with 1/32 taped lines. real panel lines are nearly imperceptable except on the removable service panels.