This ink is a medium gray on bleached papers, such as copy paper. It's a pale gray on cotton rag papers. So for best effect, I recommend bleached papers. The above was written on Sugarmade (sugarcane/bamboo). This ink is freshly made. I'm hoping it will ripen and darken further. If it doesn't, I'll try increasing the amount of acorns in the recipe next year. The fact that I saw squirrels eating these acorns this year (while ignoring them other years) makes me wonder if the tannic acid content was lower than normal. We had heavy rainfall this year and a lack of sun-- could this affect it? Squirrels usually only eat the "sweeter" acorns that are low in tannic acid, such as the white oak acorns. Unless there is nothing else to eat, they don't ordinarily eat this type because they are bitter.
The ink is very waterproof, though it turns brown once it's been soaked in water.
Sawtooth Oak Acorn Iron Gall Ink
25 parts sawtooth oak acorns, crushed (Quercus acutissima Carruthers)
2 parts iron sulfate
1 part powdered gum arabic
30 parts distilled water
Several whole cloves
This is the amount of acorns I found, so I used these ingredient amounts:
1 kg (2.2 lbs.) Sawtooth oak acorns, crushed (Quercus acutissima Carruthers)
80 gr (2.82 oz.) iron sulfate
40 gr (1.41 oz.) powdered gum arabic
1331 ml (45 oz.) distilled water
Several whole cloves
Combine the crushed acorns and distilled water into a glass jar and allow to ferment 2 months. (If the jar has a metal lid, use a Saran Wrap barrier between it and the ink when you screw it on.)
Strain through a couple of layers of cloth, squeezing every last drop of liquid you can. Cover and bring the liquid to a boil in a non-reactive pot for 5 minutes. Remove from heat. Add more distilled water if necessary to bring it up to the original amount of distilled water, 45 ounces.
Add the iron sulfate, stirring with a wooden spoon until dissolved. Add the gum arabic and stir well. Add several whole cloves (for a preservative). Let it set overnight in a clean amber glass jar. It’ll take about this long for the gum arabic to totally dissolve. Stir again. Make a writing sample. It should be a dark gray or black, depending on the paper you use. Yields approximately 40 ounces (1183 ml) of ink.
The Sawtooth Oak Acorn (Quercus acutissima Carruthers), commonly used as a landscaping tree in the southeast. I found these in a church parking lot, utterly begging me to make ink out of them.
Fermenting the crushed acorns
Here's a video for acorn ink, which uses a totally different method than mine, but the results are a lot quicker.
Edited by fiberdrunk, 04 December 2012 - 05:03.