At the last meeting the guild created walnut ink in a dark sepia tone. There are many ways of making ink but there are two main types: iron/tannin based and carbon based. The iron and tannin ink is a chemical reaction between iron (ferrous sulphate) and any plant matter that at has tannins. Walnuts, oak galls and certain types of vegetation, naturally produce a 'tea' when soaked and then by boiling this down you get a thicker more concentrated liquid. With the addition of iron (we used rust collected by one of the members) the chemical reaction happens and the liquid turns black. The depth of the black depends on the concentration of the tannins. A weaker mixture will produce a lighter ink.
We experimented with the fruit of the black walnut, using approximately 20 and soaking them for a few weeks in rainwater. We strained the water and began reducing the liquid on the stove. When the water level was down by about half we added the iron. From there it is a matter of colour preference, we continued to boil the ink down to get a richer colour. Finally gum arabic was added so the ink would bind to paper or parchment.
What an honour, this particular batch was sent as a gift to an Emperor and Empress of the Adrian Empire!
