Paula Artal-Isbrand, Objects Conservator at the Worcester Art Museum, presented the various ways in which she uses paper in her objects treatments. She shared some background on paper types. Asian papers typically come from the paper mulberry tree and produce long fibers (kozo) and strong paper or from the gampi tree, producing shorter fibers to make crisp and translucent papers. Mitsumata shrubs are a third source, but not part of this presentation. Western papers are more often made from cotton, linen, flax, or hemp. Paper in conservation is strong, inert, compatible with conservation materials, has excellent long-term stability, and does not pose health risks. It can also be manipulated to mimic a wide range of materials through inpainting and coating. By choosing the right coating materials, the translucency and texture can be adjusted to fit the application. These papers can also be inpainted with standard inpainting materials to match color and texture.
Artal-Isbrand outlined two ways for thinking about how to use paper. First, it can be used as a restoration material. Artal-Isbrand offered several examples of how she’s used paper in this way. For example, she used acid-free matboard cut into shape for a loss repair in a fan. For archaeological glass, she toned paper kozo paper with watercolors (not with acrylics since they would create too much opacity) and impregnated the paper with Paraloid B-72, acrylic co-polymer. The toned and resin soaked fill was a perfect match for the glass and was attached with Paraloid B-72. She has made paper fills to reconstruct chain mail, for joining heavy elements of an iron helmet, for reinforcing failing solder joins for bronze armor, and for backing a Roman lead curse tablet that needed to be unrolled. These repairs were carried out using a combination of kozo paper with Paraloid B-72, and are a testament to the paper’s strength. Artal-Isbrand also described that paper can be an interlayer between an artifact and fill material to ensure reversibility and how cellulose powder can be a bulking additive for fills, and if toasted, can also impart pigment to fills.
Second, paper can also be used as a tool. It can work well as a facing for an intermediate phase of treatment. It can also serve as a barrier layer. For example, thin papers are a great barrier film for gels. Here, Artal-Isbrand mentioned that thin gampi paper can be good for this. The paper is placed between the surface and the gel, allowing for easier clean up in gel removal. Paper can be a poultice material. Artal-Isbrand uses Whatman cellulose powder, which will cling well and hold the poultice solvent. For these same reasons, shredded filter paper soaked and blended in water can be used to create a mold of another artifact. The mold should be sealed with resin (for example, Paraloid B-72) to keep it from getting damaged by water applications. If using the mold for creating a plaster fill, this step is critical.
During the question / answer period, there was a brief discussion on how shredded paper serves well for poulticing, and is better than cellulose powder or other very fine materials, because those become difficult to remove and can leave a hazy residue. So, it is important to distinguish between powder and pulp or shredded and/or ground paper. An interleaving layer can be helpful if powder is used. Also during the discussion, another example was mentioned that paper can be rolled into “worms,” impregnated with Paraloid B-72, and inserted it into losses to provide filling that is more easily removed than putties or other fillers.