Noodler’s Bulletproof Black is pretty darn archival-quality. I bought a bottle when I was briefly fascinated with fountain pens (it’s cheap too!) and tested the

Noodler’s Bulletproof Black is pretty darn archival-quality. I bought a bottle when I was briefly fascinated with fountain pens (it’s cheap too!) and tested the strength claims by soaking the paper overnight. No ink loss, though the paper came apart when I tried to get it back out.