f89, f102: folds planned, then shifted towards spine?

[Jorge_Stolfi]

There are in fact traces of other folds that do damage glyphs willy-nilly. But what stood out to me is that on these two foldouts, there are indications of fold-avoidance, and in both cases at some distance outward from the current fold. The spacing isn't random, because on both foldouts, a similar behavior is seen on the recto as on the verso. The scribe places their paragraphs or word spaces based on where they expect the flap fold to be.

Indeed, I agree, the Scribe definitely avoided the blue fold on the bottom parag of f89r2 and on all but the first and last parag lines of f89v2.

However, on the figures and on some text lines he clearly did not avoid it. 

Moreover, planning for a future fold, other than the  would be quite uncharacteristic of our Scribe.  He did not do so on the Zodiac pages.   

So I retract my conjecture and offer a new one.  When the Scribe started to work on that bifolio, it already had three vertical folds dividing each side into three full-width pages and a half-width one; the latter one with an irregular edge. The third fold was the blue one of your figure; the pink and green folds did not exist yet.  

The Scribe worked on the two full-width pages adjacent to the straight edge as separate pages, but decided to use the remaining one-and-a-half pages as a single page.  He did tend to avoid the blue fold when writing the text -- but only because the curvature of the vellum along that line made it difficult to write well-formed glyphs.  Not because he thought that there should be a blank margin around that fold.  That was not a problem for the figures, however.

Presumably, for a while the completed bifolio was kept folded along the three pre-existing folds, including the blue one.   At some point it was folded along the pink line instead; but not for long.  Eventually it got folded along the green line, an that is how it remained to this day.

All the best, --stolfi