Plant-based inks

For example: black iron gall ink

Metal-based inks can degrade over time and damage the substrate.

Ingredients: plant extracts (gallnut, bark containing tannin such as chestnut or walnut, etc.), gum arabic, iron sulphate, preservative.

Tools: mortar, pestle (or coffee grinder), container, feathers

Media: paper

Ingredients: Oak galls, water, iron sulphate, gum, essence of thyme (example).

Recipe: Grind the oak galls. Bring 200 ml of water to the boil and pour over 13 g of ground galls. Leave to infuse for 1 to 12 hours. Squeeze into a cloth and collect the brown liquid. Add some iron sulphate (approx. 7g) to the liquid. Reduce over a low heat until the desired concentration is reached: about 10 cl. Add 10 g of gum water for 10 cl of ink. At the end, add 1 or 2 drops of thyme essence or other preservative.

Recommendations: Iron sulphate should be used as little as possible, as iron tannic ink can degrade and become so acidic as to destroy the cellulose of the paper base by the formation of sulphuric acid from the ferrous sulphate.

Manières de peindre, Jean-Pierre Brazs, Editions Notari
Encres de plantes, Elisabeth Brémont, Ulmer
Couleurs végétales, Michel Garcia, Edisud