ブックタイトルConservation and Restoration of Western Paper

概要

Conservation and Restoration of Western Paper

Iron Gall Ink on Paper:Main Considerations for Their ConservationAlejandra Odor ChavezHead of Conservation, National Archives of MexicoIron gall ink has been the most used blackink for Western manuscripts in the lastthousand years. It has been used for writingand drawing on supports like parchmentand paper, and will be present in almost anycollection with Western documents previousto the 20th century. It can be defined asan ink formed from the aqueous solutionof gallic acid and iron salts, forming a dark(usually black) organic-metallic complex,commonly bonded with some natural gum.The main damage iron gall inks may causein paper is known as ink corrosion, and it iscatalyzed by iron ions and sulphuric acid,both provided by the main components ofthe ink.As in other Western countries, Mexicanarchives and libraries house kilometersof documentation with iron gall inks,with the added complexity of the variousenvironmental conditions given by the widevariety of climates throughout the country,that can directly influence their risks anddamage rate.History and technical evolution ofiron gall inksThe reaction of tannins and iron salts toproduce black color is known since antiquity.In India, in the 4th century B.C., thismixture was used as a hair dye, and Pliniusdescribes, in the 1st century, an experimentin which metallic salts reacted with apapyrus impregnated with tannins, resultingin a black color. Another example is theshoemaker’s ink used in Roma to darken skinsused for the manufacture of shoes. 1As in Eastern cultures, carbon inks were themost commonly used black writing inks inthe West before the appearance of iron gallinks. These consist in a simple suspensionof carbon particles in water, with a gum asPhoto 1 Iron gall ink on paper, National Archives of MexicoPhoto 2 Iron gall ink on paper, National Archives of Mexico45