Iron Gall Ink Treatment
Background: Iron gall ink has been used for the last several centuries, and some formulations can be extremely corrosive to documents. The ink can render manuscripts and other documents illegible and inaccessible by causing loss of text, bleeding, fading, strike-through and acid migration. This process, known as ink corrosion, is very difficult to arrest without further loss or change to the appearance of the ink. The Conservation Division and the Preservation Research and Testing Division in the Library of Congress have recently concluded two projects that further the continuing efforts to treat artifacts suffering from iron gall ink corrosion.
Contributing Studies:
Connelly Ryan, Cindy, et al., “Optimizing Ink Corrosion Treatment Protocols at the Library of Congress,” Institute of Paper Conservation 5th International Conference Papers, Edinburgh, 2006, Institute of Paper Conservation/Institute of Conservation, UK. S. Jacques, ed. London: ICON, 2007, 195-202.
Biggs, J., et al., “Treatment Trees for Iron Gall Ink: Using Flow Charts to Develop Treatment Protocols,” Institute of Paper Conservation 5th International Conference Papers, Edinburgh, 2006, Institute of Paper Conservation/Institute of Conservation, UK. S. Jacques, ed. London: ICON, 2007, 211-218.
Project Description: The Preservation Directorate initiated this project in 2002. An internal Iron-Gall-Ink-Corrosion (IGIC) group tested treatment protocols commonly used by the Conservation Division alongside recently developed European protocols. The first phase of the project was completed in mid-2005 and the group identified a variety of successful treatment options that could be used for typical Library of Congress artifacts, depending on the chemical make-up of the collection item and its physical condition.
A second internal Protocols for Iron-gall Ink Treatment (PIT) Group subsequently developed examination and treatment guidelines for staff to use on iron-gall ink-inscribed artifacts. A unified approach to the preservation of iron gall ink artifacts in LC collections was developed, to insure consistent practices in treatment and documentation.
Outcomes/Findings:
- Eight treatments were applied to standardized ink samples on three types of paper, representing a range of current practices including water only, alkaline buffering with calcium or magnesium bicarbonate, ethanol-modified alkaline buffering, and combinations of calcium- or magnesium- phytate chelation with the alkaline treatments. Samples then underwent one of six periods of accelerated aging, and laboratory analysis.
- No single treatment gave superior results for every property examined. Selecting an optimal treatment method will depend on the specific needs of each artifact.
- Treatments including phytate salts generally performed better than or as well as alkaline buffering alone. The ethanol-modified alkaline treatment often gave better results than the aqueous ones.
- Systematic differences were observed between the gelatin- sized rag paper samples, and those on unsized papers. Since most of the Library’s collection items bearing iron gall ink are on sized rag paper, this suggests caution when interpreting research performed only on unsized paper.
- Based on the research results and evaluation of trial treatments, decision-making flowcharts called "Treatment Trees" were developed.
- A substantial number of artifacts were treated, to be displayed in the Library's exhibit spaces in the Thomas Jefferson Building and the new Capitol Visitors Center .
Support: Library of Congress Library Services
Acknowledgements: Library of Congress and the staff of the Preservation Directorate
Update and Images:
March 2007: Results of both research efforts were presented at the Institute of Conservation (ICON) 5th IPC International Conference in Edinburgh.
April 2008: Case studies of manuscript treatments guided by the flowcharts were presented at the American Institute for Conservation (AIC) 34th annual meeting in Denver, CO, and will appear in the associated postprints.