When last we left Paul Bartsch’s field book of marine invertebrates—nudibranchs—from the oceans surrounding the Philippines, initial stabilization had been completed so that the volume could be digitized. Stabilizing the volume included removing the original interleaving tissue, which had begun to deteriorate and discolor adjacent pages, and replacing it with archival interleaving; fully disbinding the field book by removing remnants of sewing thread and spine linings; and making an inventory of the specimen illustrations to ensure all drawings remained accounted for throughout treatment. For ease of handling, folders made from archival paper were prepared for each gathering of pages.
Since our first post, digitization has been completed, and I have turned my attention to the volume’s continuing treatment.
As noted above, the original interleaving had been removed, and while new archival interleaving tissue was cut to size and prepared, it had not been adhered in place to facilitate clear imaging of the specimen illustrations. Thus, the first step in the continued treatment was to attach these using cast-out films of an acrylic adhesive, Lascaux 498HV. Attaching these first allowed the interleaving to perform its protective function throughout the duration of the treatment. Small pieces of the films were cut to size, mimicking the size and shape of the original spots of adhesive used to attach the original interleaving, placed, and reactivated with a heated spatula applied through silicon release paper. Any spots where the illustrations had become detached from the book’s pages were treated in the same manner.
A handful of illustrations, with one in particular, had become damaged over time. Due to the delicate nature of the paper on which these drawings were executed, treatment options were carefully weighed. Too much moisture could distort the paper, and many heat-set tissues would diminish its transparency. I ultimately selected a solvent-set tissue, one which has been coated with an adhesive that is reactivated when wetted with a solvent; since this will evaporate more quickly than water, there is less chance for distortion. I carried out the treatment atop a light box, to better align the torn edges of the paper. I chose a very thin tissue, which allowed me to shape and place the repair paper in situ, coated side facing down, then apply the solvent from the uncoated side of the solvent-set tissue. The solvent wicked into the paper and began the adhesion process, and then I allowed it to dry under weight.
The next step was to mend broken pages throughout the volume. This was carried out using medium-weight Japanese tissue in a matching tone, with wheat starch paste as the primary adhesive. The majority of the broken pages were split along the spine folds of the gatherings; these were “guarded,” meaning they were mended or reinforced along this fold, in order to be both intact and strong enough to support new sewing when the book is reassembled. Edge tears and cracks were also mended or reinforced as necessary.
With these tasks completed, the next step is to resew the book and recreate a functional volume. Stay tuned for another post with a final update!
- Coming Soon to the Transcription Center: Department of Invertebrate Zoology, The Bigger Picture, Smithsonian Institution Archives
- Conservation, Smithsonian Institution Archives