Table 1 Classification of iron gall ink damages according to Reissland and Hofenk de Graaff (2000)

From: Combining phytate treatment and nanocellulose stabilization for mitigating iron gall ink damage in historic papers

Good condition (condition rating 1)

No or light brown discolouration, no mechanical damages, normal careful handling

Fair condition (condition rating 2)

Dark brown discolouration, ink penetration, no mechanical damages, special care in handling necessary

Poor condition (condition rating 3)

ink penetration, mechanical damage (cracks), handling by a knowledgeable person with support still possible

Bad condition (condition rating 4)

ink penetration, severe substance loss, handling only with the risk of loss (restrict handling, with support)