probable plant ink

Ingredients

gallic acid

Preparation Steps

Original Recipe Text

Likely composed of plant-derived tannins/gallic acid without added metal salts. The author hypothesizes that 'the gallic acid contained in the ink reacted with the iron in the support, creating an iron-gall ink' (p. 118).

Evidence

"Even if it is not easily distinguishable, one can see a shadow under NIR light in Figure 4.26b, following the same pattern as the ink, a characteristic sign of iron-gall ink. However, characteristic of a carbon ink or a plant ink, no addition of iron can be detected when passing from the support to the ink, as can be seen on the XRF spectra presented in Figure 4.26c."

Remarks

Observed in manuscript Mosseri Ia.5 and others listed in Table 4.12. The ink shows a shadow under NIR (typical for iron-gall), but XRF shows no increase in iron or other metallic components compared to the paper support. All five identified occurrences were on paper (p. 118, 120).