Condition rating for paper object with iron-gall ink

The acids and metal ions present in ink can cause paper or parchment to deteriorate, a process known as ink corrosion. This publication provides readers with an insight into the four stages of deterioration.

It explains a method which has been specially developed to measure the damage caused by ink corrosion. The severity of the degradation of each object is expressed as one of four categories: good, fair, poor or bad. This rating can then be used as a basis for drawing up a treatment plan. This brochure shows exactly how paper degrades as a result of ink corrosion. It also explains how to recognize the extent of any deterioration.

Iron gall ink

The earliest documents written in iron gall ink date from the first centuries of the Common Era. The ink’s indelible character ensured its popularity into the twentieth century. For years, the Netherlands Cultural Heritage Agency has been carrying out research into the causes of ink corrosion with the aim of developing appropriate methods of conservation. The four stages of deterioration described in this brochure are visible to the naked eye, enabling any damage to be identified easily and quickly. The brochure also includes instructions on how to store and handle the documents at each stage.

This publication is also available in Dutch.

Who is this publication for?

This brochure is intended for owners, managers and conservators, who are dealing with the management and preservation of written historical documents.

Publishing details

ICN information no. 1
Writers: Birgit Reißland and Judith Hofenk de Graaff
© The Netherlands Cultural Heritage Agency, 2001