Bad news: f116v was substantially mangled by Retracer

[Bernd]

The ink has surprisingly coherent albedo over UV and VIS and only becomes transparent in far IR. The only obvious exception is 'vix' where there's a rightward downstroke in the 'x' that clearly is something else than iron gall ink. Transparent in UV, visibility increases throughout BGR as wavelengths increase and becomes strongest in IR. What is this? the stroke appears to start exactly in the leftward downstroke of the 'x'. Coincidence or intended?

   

The 'i' contains an exceptionally thick layer of ink and looks like it was overwritten, but with normal ink. There appears to be a small horizontal stroke underneath.

Here's a spread spectrum UV-Y-IR image I made by mapping the longest, a medium and the shortest wavelength to RGB channels
940nm IR0 -> R
570nm AM0 -> G
365nm UV0 -> B

570 nm Amber renders the vellum in a more natural tone, otherwise there is no big difference from 535 nm Green - so I used AM for the Green channel.  You can see the Iron gall ink in red while the rightward downstroke in the 'x' is black.

   

Also what is going on in the 'g' of 'gas'? How was this character drawn that it contains a horizontal rightward stroke into the 'a'? the 's' has a vertical downstroke. But these are indistinguishable from the ink throughout the spectrum so probably made by the author during writing.