Ink/pen dynamics and the rhythms of writing

[ReneZ]

These are excellent examples, and quite close parallels to the Voynich MS, in my opinion.

I suspect the scribe of the St.Gallen MS is more expert. The strokes from upper left to bottom right (and possibly v.v.) are consistently broader than those from bottom left to upper right (and v.v.).

The example p196a suggests a  touch-up, just like in many places in the Voynich MS. However, I don't know if that can really be concluded.

We need to remember that iron gal ink is originally quite light, and it only darkens after writing, due to a chemical reaction (oxidation) with the parchment. I could easily imagine (but do not know) that varying properties of the parchment could cause the effect that we see.