Conservators mend paper using a variety of techniques depending on the type of paper, media, or artifact that comes across our bench. One material we use frequently in the Indiana Historical Society Conservation Lab is pre-coated repair papers. These are fabricated in-house and are customizable to a specific project or type of paper that we are working with. Long-fibered papers are selected in an appropriate thickness then coated with various adhesives that have specific properties needed for particular projects. The papers are dried and when needed for treatment the adhesive layer can be reactivated using either very little water, solvent or heat. For this reason, pre-coated repair papers are extremely useful when repairing water sensitive objects that could otherwise be damaged while performing more traditional mends with long-fibered paper and wheat starch paste.
This week I had to prepare a World War II-era terrain handbook for digitization. This book contained several foldout maps throughout and was stapled through its side, which prevented the maps from being easily accessed. Most of the larger maps were printed in black and white on coated paper, which is very sensitive to water, so I turned to pre-coated repair papers to stabilize these maps for safe digitization.
First, the rusty staples were removed to free all of the pages. Next, the entire book was surface cleaned to remove dust and grime. Because this handbook had been used, many of the maps were creased or slightly torn. The creases were locally relaxed and flattened, then the tears were mended with a pre-coated repair paper made with very lightweight Japanese long-fibered paper and coated with sodium carboxymethyl cellulose (SCMC), a cellulose ether. SCMC is a totally reversible adhesive which reactivates with very little moisture and creates a flexible mend, a crucial characteristic as these maps would need to be refolded after scanning. Using the SCMC pre-coated paper for this treatment allowed me to mend the torn areas of the maps without disturbing the water sensitive coating on the paper.