Så här står det under
http://www.newyorkcarver.com/scriptoria2.htm:
Ink - an improvement over the ancient world's use of water-soluble, carbon ink was the medieval mix of pulverized Oak Gall, copperas and gum Arabic. The ingredients yielded a much more permanent, though if mixed improperly, highly acidic ink. One old recipe gives advice on the proper proportions:
<i>"...a quarte of water two ounces of right gumme Arabick, five ounces of galles, and three of coperas. Let it stand in the warme sunne, and so it will the sooner prove good inke."</i>
Mistakes were common, and evident in many old manuscripts slowly eaten through by medieval ink, from Lt., encaustum, or "burnt in."
Möjligen står det mer på samma sida.
/Henrik