If the Shoe Fits: Conservation of a Tudor Leather Shoe

Editor's Note: This blog is the first in a two-part series on a case-study of archaeological conservation and public engagement with amateur archaeology groups. The first post will focus on the conservation of the leather shoe in question, and the second will discuss public engagement between Cardiff University Conservation and London Mudlark.

This spring, I had the pleasure of working with London Mudlark Lara Maiklem to conserve a 16th century Tudor leather shoe discovered on the Thames foreshore. The waterlogged fragments recovered constituted a nearly complete shoe, a rarity in archaeological conservation. The fragments were in excellent condition, thanks to the measures Lara took while seeking a conservator for the shoe. In addition to the exciting task of conserving and reconstructing these fragments, I was also eager to get to know Lara and to engage with other people that mudlark on the River Thames. In archaeological conservation, public engagement with amateur archaeologists and groups such as London Mudlark is a key aspect of education and public archaeology.

Figure 1: Waterlogged Leather Fragments Before Treatment Side 1

Figure 2: Waterlogged Leather Fragments Before Treatment Side 2

The treatment of the shoe was relatively straight forward prior to reconstruction. The fragments were cleaned with water and brushes to remove dirt and sediment present from their burial environment. A chelating agent was subsequently used to remove iron ions which penetrated the leather and caused discolouration of the material. Finally, the fragments were impregnated with a bulking agent in order to displace the water.

Waterlogged organic materials often experience cellular degradation due to the prolonged presence of water throughout the microstructure of the material. In the case of waterlogged organics, controlled drying is imperative to prevent cellular collapse which may cause warping, shrinking, cracking, etc. For this reason, a bulking agent, such as polyethylene glycol (PEG) or glycerol, may be employed in a laboratory to support the deteriorated structure.

Following the use of a bulking agent, the fragments were placed in a freezer and then freeze-dried. The freeze-dryer causes the frozen bulking agent (as well as any frozen water molecules left behind) to sublimate, effectively causing the frozen liquids to become gaseous. By bypassing the liquid phase of the bulking agent and water, expansion and contraction of the organic material can mostly be avoided. This is an effective way for conservators to avoid shrinking and cracking during drying of waterlogged organics.

Figure 3: Leather Fragments After Freeze-Drying Side 1

In this case, the leather presented with an excellent state of preservation. The leather was generally thick and quite flexible, even after impregnation and freeze-drying. The artefact's condition informed the choice of materials that were used for reconstruction. To assist in reconstruction, the fragments were shaped on plastazote during freezing and freeze-drying. A combination of adhesive and thread was used to reconstruct the fragments. Adhesive was used to hold the two insole fragments to the outsole of the shoe. As the insole fragments were the only ones without stitching holes present, this was the only area where an adhesive was necessary. The toe box and heel counter fragments were attached to the outsole of the shoe using brown linen thread through the existing holes. The strength and thickness of the shoe allowed for a more durable fibre to be used.

Figure 4: Leather Shoe After Treatment

Figure 5: Leather Shoe After Treatment

This was an exciting project to be involved in, and I loved working with a waterlogged organic material. Overall, I was pleased with the condition and aesthetic of the object after treatment, and it was a welcome challenge after working primarily with metals and inorganic materials. Furthermore, the artefact provided a unique case-study to evaluate public engagement between conservators and amateur archaeology groups -- a topic I will evaluate in further detail in the following blog post.

Thanks for following my conservation-related adventures!

#conservation #archaeology #organics #leather #Tudorhistory #marinearchaeology #publicarchaeologicalconservation