Parchment
The parchment, otherwise known as “vellum” is formed using the skin of an animal, which has been prepared by pumicing and scraping both the hair and flesh away to provide a surface for writing upon. The characteristics of the parchment which can confirm the animal species include follicle patterns and veining (AIC Wiki 2024).
What animal?
Under microscopic analysis, it was determined that the characteristics needed to identify the species of animal had deteriorated. By using historical sources, we can attempt to discern what was likely to have been used.
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The deteriorated parchment against the restoration parchment. 200x magnification.
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Calfskin and sheepskin were predominantly used for parchment, however calfskin had the advantage that it could take erasure well.
According to the Dialogue of the Exchequer, it was preferable to use sheepskin for legal documents, as it was not easy to make an erasure on sheep skin without it showing. This was seen as desirable for legal writs as evidence of tampering would be immediately visible (Turner, N.K (2018).
Parchment restoration.
During the 16th century restoration of the wax seal, it is possible that the parchment had undergone treatment at the same time.
The original parchment, worn and deteriorated, needed to be supported. It can be observed that it has been attached to a new piece of vellum, which we have identified as goat skin. This was likely to have been attached using an animal glue adhesive.
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The wax seal has then be reattached to the charter using new green threads, which are noticeably more vibrant than the colours on the faded silk cord.
Wear and tear.
The areas of loss of the1262 charter is likely to have been as a result of the parchment having been folded. The parchment appeared to have been folded in half, and then folded again.
This has resulted in the fold lines to be susceptible to abrasion. The damage appears to be running parallel to the observed fold lines.
A window to the soul, perhaps?
On the recto of the parchment, a window reveals two lines of script from the verso.
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It is unclear if this was deliberately restored in this way, or if it was a later repair to mend a hole that had formed since the goat skin restoration.
You've got some gall!
Through XRF analysis, we have identified that the ink used was iron gall ink due to the presence of iron.
Starting from the 12th century, iron gall inks were widely used for their excellence to produce an intense black colour (Ferretti, A. Sabatini, F. Degano, I. 2022).
The iron gall ink was produced by crushing the galls of oak trees and soaking them in water for several days.
A 1483 medieval recipe for iron gall ink that is held in the UK National Archived follows:
to make iron gall ink, combine in equal measures oak galls, copperas, gum Arabic and water.
Gallic acid tannins are released, and when mixed with the copperas (iron sulfate), an intense black colour is produced. The gum Arabic acts as a binder, to help the ink flow and bind to the parchment (Peverley, S. 2014).
Issues can arise from the presence of gallic acids, with the fading of the text and paper acidification, which leads to the subsequent degradation of the parchment. The ink of the 1262 charter appears to be in a stable condition, with no signs of deterioration caused by the iron gall ink.
