Beige stain on 93r

[Jorge_Stolfi]

The paint would tend to form puddles, basically 'lie' on top of the parchment and take forever to be absorbed by the parchment, let alone get dry.

In general, paints and painting techniques that work on paper should not do well on vellum.

When paint and ink are applied to paper, they flow into it and get trapped by the fibers.  That provides some resistance against abrasion and humidity. And that is why lampbrack (china, india) ink is the best ink for paper.

But parchment is not supposed to absorb paints and ink like that.  Lampblack ink would just sit on top of the parchment and would be easily rubbed off. That is why writing on vellum only makes sense with iron-gall ink: because as it oxidizes it turns into an insoluble polymer that is chemically bound to the proteins in the vellum.

All the best, --stolfi