Materials and method

• Galls, 3 parts by weight
• Water, 30 parts by weight
• Ferrous sulphate, 2 parts by weight
• Gum arabic,1 part by weight

Figure 4: Crushed acorn gall Image courtesy of Gianluca Farusi	Figure 5: Filtering the water and crushed gall mixture Image courtesy of Gianluca Farusi
Figure 6: The three inks Image courtesy of Gianluca Farusi	Figure 7: The results! Image courtesy of Gianluca Farusi

1. Break the galls into pieces, then grind them in a coffee mill (Figure 4).
2. In a beaker, add the water to the ground galls. Leave the mixture to ferment in a sunny corner at room temperature for 3 days.
3. Filter the mixture (Figure 5) and add the ferrous sulphate to the solution. Stir well and leave for 3 days.
4. Add the gum arabic, stir the mixture and you have your ink (Figure 6). Time to start writing (Figure 7)!