Wednesday, March 18, 2020

Super Size Me: The Book Conservation Variety, Part 1

In the coming weeks, we will be publishing a series of posts documenting the extensive treatment of one very large leather bound volume. Following is Part 1 of the series.

The Royal Commentaries of Peru, 1688, before treatment

The Royal Commentaries of Peru (RCP) by Garcilaso de la Vega (1539-1616), published in 1688, is a large volume covering some of the history of the Incas, including their government and laws and the Spanish invasion of their countries. The RCP landed in Preservation Services having already received multiple repairs and treatments over its lifetime, including a Polyvinyl Acetate (PVA, similar to common white glue) adhesive applied to parts of the leather cover, leather patches, and a strip of adhesive tape to mend the exterior hinge.

Before treatment, the textblock was split and
the book had received multiple repairs
Likewise, the book showed signs of extensive use, such as well worn foreedge corners, scratched and worn leather, and broken hinges. The textblock sewing was broken in places and the the textblock was in multiple sections. The binding was a tight back leather binding, so the leather rested against the spine edge of the text with minimal spine linings between the leather and paper.

Due to the PVA adhesive applied to the spine, the first section of the book was restricted from properly opening. Adding insult to injury, the book was originally printed and bound with the paper grain running perpendicular rather than parallel to the spine. As mentioned in an earlier blog post, the grain direction of the paper can affect how well the book opens and whether the pages drape or lay flat for easy reading. There isn't much to be done about the paper grain direction once a book is printed and bound, but there are a few techniques to lessen the impact and improve the function of the book.

PVA adhesive applied to the spine restricted the opening of the pages

A leather patch and PVA adhesive had been
applied during previous repairs
We do our best to conduct the least invasive conservation treatment that will stabilize a book and improve its function. Our goal is to maintain as much of the original item and experience as possible. In the case of RCP, we decided the best path forward would be to remove it from its damaged binding, which had already received numerous treatments, some more effective than others. The leather was too brittle and some of the treatments were partially irreversible, so a new binding was the best way to proceed.

The first step in the process was removing the covers and cleaning the spine. The original leather label was carefully lifted by facing it with Japanese tissue and Klucel-G (a leather consolidant). Because the label was very brittle, the facing tissue provided the strength and stability needed to lift it from the spine.

Prior to cleaning the spine, the original leather label was lifted by
facing it with Japanese paper and Klucel-G, a leather consolidant

The spine was cleaned by mechanically removing easily friable layers, followed by the application of a poultice of rice starch paste to soften the old adhesive. Once the spine was cleaned, it was clear that previous repairs had disguised much of the damage to the spine edges of almost all the folios. Thus, an extensive guarding project was at hand. Guarding is the process of attaching two paper leaves at their spine edges with a strip of Japanese paper and starch paste. The folios can then be sewn through the fold to reconstruct the text block.

Left: Separate leaves waiting to be guarded
Right: Stacked sections of the textblock already mended and ready to sew
RCP is just over 1000 pages and almost every folio needed guarding. Needless to say, this phase of the project was time-consuming. But, slowly and over time, the stack of leaves became a stack of guarded folios.

Once the text block was fully mended, sewing commenced. In order to minimize the swell produced when thread is sewn through every section (a section is several folios seated one inside the other), the book was sewn in a pattern called "two on". Just as it sounds, two sections are added at a time and the thread alternates from one section to the other so that half the amount of thread goes through any one section. This keeps the spine edge of the book from being disproportionately larger than the foreedge of the book.

A sewing frame was used to support the cords while the sections are sewn together along the length of the spine

The book was sewn on cords. For a particularly large book such as this (roughly 8.5"W x 13.5"H x 3"D), the cords provide extra strength and support as the book is handled. By guarding the folios and resewing the book, it has become much more functional for the reader as it flexes open more easily and is much stronger than before, not to mention it is in one piece again!

Stay tuned for Super Size Me: The Book Conservation Variety, Part 2 to follow the steps of sewing endbands, board preparation, and lacing the covers to the textblock.

No comments:

Post a Comment