The Iron Gall Ink Website

Risk factor - High humidity & water

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


The occurrence of brown discoloured halos around ink lines and on the verso of objects is the ultimate sign: ink corrosion! However, a lot of objects do not show such halos. We can understand the present condition of objects by explorig their past. You will find that objects that today are severely discoloured, at least once in their past suffered from a water incident (a leakage, a flood, extinguishing a blaze etc.), or were transported over long distances under bad environmental conditions, or were written in a moist tropical climate, or underwent an inappropriate humid or aqueous conservation treatment. Our web-tutorial illustrates how high levels of humidity (>70% RH) cause the migration of soluble components, while low humidity levels (<70% RH) are safe.