The first thing Rachael did was to define the types of damage present in the parchment sheets and to determine the grade of deterioration. The fire and water have almost destroyed the book and the sheets left are badly damaged. The different types of damage and extent of each are recorded.
The most obvious one present in all the sheets is the planar distortion of the surface. Some of the creases are so stiff (due to the heavy gelatinisation) that it will be impossible to flatten them to any better degree.
These distortions are also caused by the heat of the fire which has shrunk the parchment. As a reference, we have taken a picture of a letter P present in the same area as another P. The only difference is that one P on the parchment was affected by the heat at a different grade than the other P, where the parchment has shrunk and is less than half its original size!
Two letters P of different size due to parchment reaction to heat
Creases and tears are found in various areas, mostly on the edges of the sheet.
Creases and tears are present in most of the parchment sheets.
Some sheets have calcite on the surface; this is a typical degradation product of parchment that has been subjected to moisture and high temperatures. Calcite is present within the structure of the parchment, but, under these conditions, migrates to the surface.
The white powder on the surface of the sheet is calcite.
Another type of damage is severe gelatinisation. Gelatinisation is a degradation process catalysed by high temperature in which the collagen changes its structure irreversibly (denaturation). We have rated the damage in terms of severity at G1, G2 or G3. All of the gelatinisation recorded was rated G2 (full glass layer) or G3 (full penetration of parchment- transparent).
Gelatinisation rating G2: the parchment has stiffened and started to become translucent.
Gelatinisation rating G3: the parchment has deteriorated into pure gelatine.
There are some areas where the parchment is so curled that the text is hidden between the folds.
Folded and curled parchment is hiding the text.
The metallogallic inks, presumably due to the heat, have darkened greatly and from the original brown have become almost black. In some areas the ink is flaking off and in some other parts it has completely flaked off leaving a lighter colour on the parchment.
The burnt ink is flaking off the surface.
Traces of the ink applied on the surface of the support.
Last, but not least, you can’t miss out the dirt and stains in this whole collection of different types of damage.
Dirt and stains.
This job is going to be very challenging, let’s see what Rachael will come up with!