In the Middle Ages in Europe, writing was done with pen and ink.
There were two main recipes for making black ink in medieval Europe. The first is carbon ink, which is made from coal or lamp smoke mixed with glue. The second type is metallic gall ink, which is usually made from a solution of tannic acid and ferrous sulfate. Glue is also required to make the ink more viscous. The black color is the result of a chemical reaction.
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Metallic gallnut ink began to be used as early as the 3rd century AD, and was only seen in written records in the early 12th century. Medieval parchments were mostly written with metallic gallnut ink. Metallic gallnut ink The invention was most likely inspired by the magical properties of oak gallnuts.
Oak gallnut is a spherical tree tumor that grows on the twigs of oak trees. After the gall wasp lays its eggs on the twigs, it forms a soft dark green ball around the larvae. When the larva inside hatches into an adult, it burrows into the cocoon and flies away, leaving behind a shell rich in tannins and gallic acid.
These shells are easily broken under the action of rain and sunlight. Sometimes people use white wine or vinegar instead of rainwater. This is the first ingredient of metallic gall ink.
The second ingredient is ferrous sulfate, also known as green vitriol. It was extracted naturally in the late 16th century by evaporating water from iron-containing soil. It is possible that green vitriol was made by injecting sulfuric acid into scrap iron nails, filtering out the liquid, and adding alcohol. Then add the oak gallnut solution to the green vitriol and stir it with fig branches.
As a result, the brown-black solution slowly turned into black ink. Then add some gum arabic to increase the viscosity and concentration of the ink. Quill pens require the stickiness of gum, but later fountain pens do not. The metallic gall ink darkens when the parchment pages are exposed to air. It penetrates completely into the parchment page, doesn't rub off as easily as carbon ink, and has a more lustrous finish.
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