Back in October of 2022, The Preservation Lab had the pleasure of hosting Book Conservator, Jeff Peachey, for a week-long workshop on Conservation of Leather Bindings. One of the topics that was mentioned, but not discuss in depth, was leather facing.

No one in the lab had ever faced leather before, so Sr. Conservation Specialist, Jessica Ebert, and I decided to conduct some tests to understand the process, the best materials, and tools. With the research available, Jessica and I focused primarily on two sources, Conservation of Leather and Related Materials by Marion Kite and Roy Thomson and an article written by James Reid-Cunningham entitled Leather Rebacking, for the Seminar in Standards of Excellence in Hand Bookbinding, The Guild of Book Workers, 2013.  

The primary reasons for testing out this technique was the fact that there were leather books from UC’s Archives and Rare Books Library here in the Lab for treatment and they could potentially be good candidates for leather facing.

Let the tests begin!!

Both Jessica and I chose two different withdrawn leather books to test on:

• A tight back leather book
• A leather book with false raised bands and a hollow tube

The first step was to consolidate the leather on all the withdrawn books we were using as models. The leather was consolidated with 3% Klucel G in isopropanol. Since there were different methods shown in the available resources regarding leather facing, we decided to use two different methods for facing: facing with Japanese tissue adhered with Klucel G and facing with a Crompton heat-set tissue activated with ethanol. Trying out these two different methods would help us to understand which one of these materials would work best and cause less damage/staining to the leather.

Catarina’s Test Models

After having consolidated the leather, the spine was “divided” in two sections, top and bottom, with a small portion of the spine in between. The reason the spine wasn’t fully faced was because I wanted to see if there were any changes in the leather after being faced, removed, and reattached.

For this book, the leather was very degraded, and I couldn’t get the Japanese tissue to adhere to the leather spine with Klucel G. As a result, for this model I only used the Crompton heat-set tissue method.

The adhesive on the heat-set tissue was activated by brushing on a thin layer of ethanol. Once it was activated, the heat-set tissue was placed on the spine, and with a tamping brush pressed on the leather. Using a lifting knife, I was able to remove the leather spine, leaving the middle portion still adhered to the text block for comparison.

Once the leather spine was removed, I relined the text block spine with a reversible layer of Japanese tissue and wheat starch paste. The two portions of the leather spine were lined from the back with Japanese kozo fiber tissue and wheat starch paste.

At this point, there were two different ways to follow, I could adhere the faced spines to the text block and then remove the heat-set tissue, or I could remove to heat-set tissue first and then adhere the leather spine to the text block. I decided to first remove the heat-set tissue by activating the adhesive again with ethanol and gently removing it with a Caselli spatula. Once the heat-set tissue was fully removed and the leather was dry, I reattached each portion of the leather spine to the text block with wheat starch paste.

For the leather book with false raised bands and hollow tube, the process was very similar. However, for this model I was able to try out both the Japanese tissue adhered with Klucel G as a facing method and the Crompton heat-set tissue.

The spine was “divided” in two sections: top portion was faced with Crompton heat-set tissue activated with ethanol and the bottom portion of the spine was faced with Japanese kozo fiber tissue adhered with Klucel G.

Using a Peachey lifting knife, I was able to remove both portions of the spine. On the top portion of the spine, I ended up not removing the previous hollow tube, but removed it completely on the bottom portion of the spine.

Once the two portions of the spine were removed, a new hollow tube was created to adhered to the bottom portion of the text block spine. The hollow tube was mode of Griffin Mill Broadsheet 60 gm/115 gm paper. The new hollow tube was adhered with wheat starch paste.

Again, I decided to remove the facing tissue before adhering the leather spine back on. With ethanol, I was able to remove the facing tissue from both pieces of the spine. As seen in the pictures below, while removing the Crompton heat-set tissue there was some loss of the leather along the edges and where the leather was most degraded already.

Each spine piece was lined on the verso with a Tengujo tissue and wheat starch paste. This provided some support to the fragile leather spines. The two pieces of the spine were then adhered back on with wheat starch paste.

Jessica’s Test Models

Here are a few of Jessica’s test models (she has a better eye for taking good photographs throughout the process).

Final Thoughts…

This was a great project that Jessica and I worked together. It was useful to test out different methods using different types of books with leathers in various stages of deterioration. We learned that Japanese tissue may not be able to be used as a facing material when coated with Klucel G, since in one of the tests I did, it did not adhere to the leather. This could lead to further testing, perhaps working with a Klucel G of a different concentration since we only used a 3% concentration for these tests. In addition, depending on how degraded the leather is, using a Crompton heat-set tissue may not be an ideal good solution for every item as it created some damage on the surface layer of the leather spine of our of the test books. Finally, at least in one of my models, the leather became darker than it was originally. There is still more testing and practice to do before we use this technique on a collection item, but this was a great place to start.

Catarina Figueirinhas [UCL] —- Assistant Conservator