In the Lab: Conservators Don’t Like Tape!

My latest conservation project has been one involving chemicals and special equipment, doing something that we conservators face far too often—tape removal. But fortunately, our lab is well equipped with tools and materials specifically for that purpose.

In September there will be a new exhibit at the Nasher Museum of Art on empire and cartography, organized by the BorderWork(s) Lab here at Duke. Seventeen maps and books from the Rubenstein Library were selected for the exhibit, but many of them required treatment first. Rachel Penniman, Erin Hammeke, and I have been working to make sure the items will be in safe condition before they make the short journey across campus to the museum.

One item that has required the most work for me is an early 19th century hand-colored manuscript map from South America labeled “Terrenos Incognito” (above, front and back). Although on good quality, strong paper, the map was previously folded so many times that it began to break along the folds, and so some well-intentioned person in the past reinforced the folds with strips of tape on the back. Over time, the adhesive turned yellow and seeped through the paper, leaving stains along all of those fold lines. And not only is the staining unsightly, but the adhesive is also chemically destructive to the paper, making it brittle and more liable to break. So now, as is often the case, I am spending many hours undoing someone’s quick fix that turned out to do more harm than good.

Before using any chemicals I tried mechanical means to remove the tape. First I had to remove the carrier, the plastic part of the tape that the adhesive is attached to. For that I used a hot air tool to soften the adhesive and an unsharpened dissection scalpel (my favorite tool) to lift the carrier off. But there was a lot of residual adhesive left on (and in) the paper.

After testing the adhesive’s solubility in various chemicals, I selected the most appropriate solvent. In conjunction with the use of chemicals I have been using our excellent vacuum pump and manuscript suction device, also officially known as a Stealth Sucker. I work in the fume hood to avoid breathing solvent fumes. I lay my map on the suction platen and use solvent to dissolve the adhesive, then the vacuum action draws it out of the paper. I can only treat an inch at a time and the work is very slow, but the effect is rewarding . Although there will always be some staining visible, the map’s appearance is beginning to improve dramatically. Soon I hope to have it finished, and visitors at the Nasher will be able to appreciate its beauty without the distraction of adhesive stains.

Detail of “Terrenos Incognito,” Before and After Treatment

Detail of “Terrenos Incognito,” Before and After Treatment

Post contributed by Grace White, Conservator for Special Collections, as part of our ongoing “In the Conservation Lab” series.