I hope this post inspires you to try to make some of your own acorn ink! I feel like acorn ink making is a great practice for the aspiring bard or druid! Rouchon-Quillet, V.; Remazeilles, C.; Bernard, J.; Wattiaux, A.; Fournes, L.; etal. (2004), "The Impact of Gallic Acid on Iron Gall Ink Corrosion", Applied Physics A, 79 (2): 389–392, Bibcode: 2004ApPhA..79..389R, doi: 10.1007/s00339-004-2541-1, S2CID 95990608 Sort through the broken up galls and remove any larvae or foreign objects. Weigh the galls and put them in a jar. I have a rest of walnut ink that I made a few years ago. It has darkened a bit over time, but it’s still nice to draw with. The ink once had a beautiful golden-brown color, and now has darkened to a hue that’s almost sepia. I assume walnut ink doesn’t have the best archival qualities – usually self-made inks have tannins that will make the paper brittle after a few years. I still have some old drawings and documents that I wrote with my walnut ink in 2015 – so far they still seem fine. Ink made from berries will not be bright and saturated as store-bought inks, but they have an organic beauty of their own.

a 3:1 molar ratio of FeSO 4·7H 2O to gallic acid [...] has been known to have the most chemical stability"

Optional: Making a Rust Garden

Optional step: strain the berries a second time using the muslin cloth. Gather the muslin and squeeze the juice out into the bowl.

Add a preservative (optional). Some people add a preservative such as potassium sorbate to help keep their ink stable for longer periods of time.They have varying degrees of lightfastness, i.e, some of them fade over time and much faster when exposed to sunlight.