Ink corrosion - Slow changes over time

Birgit Reissland, Frank Ligterink, Claire Phan Tan Luu (2010)

A fresh iron gall ink has a bluish purplish shade. Over time, this colour changes to brown. Also, most iron gall inks increase in opacity. Knowing the ink distribution on, but especially within the paper support is crucial to understand the present condition of an object and to predict its changes over time.   ... this chapter is in progress.