I've written of my journey discovering that the spacing between letters, as well as counterspace of each letter, is one pen width between the verticals for Historical Gothic Textura Quadrata script.
The way I was taught modern Gothic script was one pen width between the letters, not the verticals. This destroys the 'picket fence' effect achieved by doing the spacing between the verticals.

I asked Tetchubah the other day "why did the spacing change?"
She said "that the spacing changed for the same reason most of us don't calligraph "pure" gothic - it's more readable that way. Also, as more readable hands came into being I suspect that their influence bled over to scribes doing gothic, and of course gothic eventually fell out of fashion. What I mean by bled over is that if you've practiced one hand extensively, it tends to influence how you write other hands.

And, of course, except in Germany, the Gothic hand fell entirely out of fashion, entirely out of use, for centuries. When it started being re-used by non-Germans in the 20th century, the calligraphers wenton the whole for readability, not the picket fence effect.