[EpiMath]

I'm not very sure about the vinegar + steal wool part... that makes ferrous acetate pretty quickly, and what we want here is a ferro-gallate. I think there are ways of producing ferro-gallate inks without using sulfates, but historically ferrous sulfate was commonly used ( and leads to paper being eaten away over time )

[nyanpasu64]

That was just a quick experiment (not fully grounded in chemistry theory) to see what would happen, since my ferrous sulfate wasn't arriving until a day later.