Neither the Ars Technica nor the original article really talk about the staining process, reagents often made from oak galls there were brushed on the parchment

Neither the Ars Technica nor the original article really talk about the staining process, reagents often made from oak galls there were brushed on the parchment. I remember when I first saw the same kind of brown stains on a medieval manuscript and had no clue what they were: since the ink was so sloppily applied I first assumed some kind of heat or fire damage (too bad the book I was looking at wasn't written by anyone famous, so it'll probably never be imaged). The idea of permanently causing damage to a manuscript in the hopes that you can temporarily make out the text seems kind of crazy (and certainly is not a proper archival practice today!), but it happened with some frequency in the mid-nineteenth century. It seems that it actually did make certain inks more visible for a brief time, though for others it didn't work. And of course this was all at the cost of permanently marring the parchment. Here's a good article on that subject that helped me understand what was going on, which even mentions the same Cardinal Mai who applied reagents to the Ptolemy ms: http://palimpsest.stmarytx.edu/AmbrosianaArchive/ResourceDocuments/RLE_reagent_papers/chemical_treatment_palimpsests/2011_Albrecht_Tinctures.pdf http://palimpsest.stmarytx.edu/AmbrosianaArchive/ResourceDoc...