Iron gall ink repair

The local repairs on Iron Gall Ink Workshop

Historic manuscripts and drawings made with iron gall ink on paper often contain weak areas caused by local corrosive action of the ink. Once these areas develop cracks, they become highly sensitive to further mechanical damage. Ultimately, this leads to loss of valuable fragments. In such situations paper conservators depend on local repair techniques.

Often, mending is carried out locally by attaching a strip of Japanese paper with a water-soluble adhesive. This practice has one serious risk: too much moisture causes invisible but detrimental compounds (iron(II)ions, acids) to be transported out of ink lines into the surrounding paper areas, thus spreading ink corrosion. Because it takes years for this process to become visible, the risk is often underestimated. To avoid the spreading of ink corrosion during treatment, we recommend the combined use of the ”Dutch Fe-Migration Mending test“, remoisten able tissue and the sponge-blotter system. The Dutch Fe-migration mending test test is a tool to make the migration of iron(II)ions visible. It should be used before doing the actual repair takes place, in order to practice how much water the conservator can safely apply. This way the conservator is able to limit the risk of spreading ink corrosion during the local repairs.

Workshop local repairs on iron gall ink.
Eliza Jacobi and Claire Phan Tan Luu explain the interactions between iron gall ink, water, and paper, and the chemical mechanisms at play during iron gall ink degradation. They propose and demonstrate a specific repair technique with the combined use of the ‘Dutch Fe-migration mending test’ and remoistenable tissue.

In the workshop, participants will get to prepare their own remoistenable tissue with different Japanese papers and adhesives, and practise local repairs on iron gall ink using the Dutch Fe-migration mending test.
Participants will also receive a ‘how-to’ package including all the materials necessary to reproduce this technique in their own studio.