17 May 2023
Conservation of Maps in the digitisation project: Qatar Foundation Partnership – Part 2
Following part 1 of the Conservation of Maps in the digitisation project: Qatar Foundation Partnership, this second blog post will present the treatments of two maps belonging to the IOR collection of the British Library: IOR/X/10065 and IOR/X/10066. Similar to the maps presented in the first blog post, these maps also have cloth as a secondary support. In these cases, the maps were fragmented and lined on a cloth support which allowed them to be folded (picture 1 & 2). A difference with the first group of maps is that they did not have textile or silk ribbons on the edges.
These two items had the same main damage. The substrate, a paper lined with cloth, was broken or weakened in various areas of the joints where the maps used to be folded (picture 3 & 4).
The paper support on the IOR/X/10066 map is thicker and distorted, with the distortions possibly caused by its large format and the broken joins no longer creating tension (picture 5). On both maps, there were small paper tears and folds around the edges. There were also loose threads due to the fraying of the cloth along the edges (picture 6). The condition of both maps made handling and digitisation very difficult, especially due to their oversize format, IOR/X/10065 measuring 1014x750 mm and IOR/X/10066 1235x1073 mm.
The aim of the conservation treatment was to stabilise the items to function in their current role and to ease handling for the next stages of the workflow: cataloguing and digitisation.
For the decision-making process we considered the condition of the maps and their original use, to be folded and unfolded many times when used. In addition, minimal intervention, re-treatability and fit-for-purpose, principles from our guidelines, were taken into account, as well as the 5 hours limit for the treatment of each item.
Selecting and preparing materials for treatment
Our treatment proposal was then focused on re-establishing the ability to fold the maps which is convenient for handling and storage. We decided on using a cloth lined with Japanese tissue for the joint repairs, similar to the construction of the maps.
Selection of the cloth
A thick Japanese tissue would not be enough to repair areas that are to be folded multiple times. We decided on Aerocotton, a material commonly used by book conservators to reinforce book joints which is a light but strong cloth. The cloth was washed with hot tap water before its use to remove any possible sizing and additives.
Selection of the Japanese tissue
We chose an 11g/m2 Japanese tissue with kozo fibers, which is strong and thick enough to give support to the cloth and the tear repairs.
Lining the Aerocotton
Aerocotton is difficult to cut after washing, (see picture 7). Therefore, it was lined using Japanese tissue and wheat starch paste (WSP). This helps to stiffen the Aerocotton, with the Japanese tissue working as a support to make it easier to handle and to limit frayed edges. The cloth lined with the paper was left to dry on a wooden board similar to a karibari, to ensure it dried with tension (picture 7).
A second lining of Japanese tissue (11g/m2 with kozo fibers) was pasted to the lined cloth strips, since it reinforced the repairs without adding any thickness. This was carried out again on a wooden board. A plastic strip was placed between the board and the strip. This would function as a barrier and prevent a section of Japanese tissue strips adhering on the board. This way, our second lining dried stretched on the board as it protruded from the plastic strip like it would on a karibari, (video 1).
Video 1: Preparing and applying the second lining of Japanese tissue on the lined cloth strips
Once the Japanese tissue was dry, we lifted them from the karibari with a bamboo spatula. The plastic strips delimited the area that we used to paste on the map. Finally, we cut them with a water brush so that the edges had a water-cut finish: this gave a stronger attachment to the tear repairs when pasted on the maps, (pictures 8 and 9).
Once the materials were ready, we placed the maps on a blotter and Bondina, verso facing up. Because the maps were of a large format, we treated each half separately. Once they were dry, we reattached them together.
For both maps we squared and positioned the fragments of the maps carefully, leaving 3mm space gap for the joints, and kept them in place under weights. Wheat starch paste was applied with a noribake to the prepared strips previously placed on plastic strip. This made the handling easier and the application on the joint to be repaired. Once the strip was on the map, we applied some pressure with a shirobake over the plastic strip. The plastic strip was then removed, leaving the prepared strip on the map and we applied more pressure with a nadebake and with a Teflon spatula. It was left to dry with a Bondina, blotter and weights on top, (video 2 and picture 10).
Video 2: Pasting the prepared strips on the tears of IOR/X/10066
Finally, strips of Japanese tissue (7.3g/m2 with kozo fibers) were applied on the joints of the recto of the maps to reinforce the hinge on both sides of the map, (picture 11).
This treatment was successful on both maps. They can now be handled and stored safely. See video 3 and after treatment pictures 12 and 13.
Video 3: Handling both maps after treatment
Tania Estrada Valadez and Camille Dekeyser