The following are methods to address these problems:
Parchment flattening
Parchment (or vellum) that is brittle or has been folded, crinkled or cockled can be restored by humidification. This can be achieved by placing loose sheets of parchment in a damp-pack (moistened blotters with the parchment interleaved). It can also be achieved by placing the document into a humidifier chamber. If only localized areas need humidification, ultrasonic water mist can be sprayed on the parchment.
The purpose of humidification is to relax the parchment. Once it is relaxed, it can be pressed flat or stretched flat, depending on the requirements dictated by binding.
There are dangers in this process. Pressing can cause moistened parchment to become transparent, especially when it has previously suffered water damage. If the parchment is weak or has tears, the tension put on the sheet by stretching can worsen the tears. Another method for use in extremely fragile parchment is to moisten the leaves in a damp pack and use a vacuum suction table set on low to flatten the leaf, helping the process along by unfolding creases and smoothing cockling gently by hand.
Filling loss
Holes or tears in parchment can be fixed in several ways. A hole can be fixed with a new piece of parchment, which is cut to size, pared and sanded to fit the hole. It is adhered with gelatin. This method is best if the parchment must ever be humidified in the future, because the patch will withstand the application of water and stretching. An alternative method to fill loss is by using Japanese paper and wheat starch paste (or better still, PVA) to patch the hole as a hole in paper would be patched. When PVA is used, Japanese paper goes translucent and has the feel of parchment. This process is has the advantage of being easily reversible.
A tear in parchment in Medieval times was fixed with gold-beaters skin, a very thin transparent membrane made from the intestines of animals. In modern times, tears have been successfully mended using fish skin, sturgeon bladder, a variety of other animal skin products and adhesive-coated tissue.
A final method of filling minor losses and repairing tears is pulp filling. This involves applying a dry or wet mixture of ground animal skins and paper pulp (exact ingredients and proportions vary by method) along with an adhesive to the loss area to fill it. This is done with the parchment on a suction table, to draw the filling material onto the parchment. The parchment is pressed until the filler dries.
Turner, Nancy. (1994). The Conservation of Medieval Manuscript Illuminations and the Question of Compensation. WAAC. 16(1), 21-22. Available
http://palimpsest.stanford.edu/waac/wn/wn16/wn16-1/wn16-108.html
Quandt, Abigail. (1996). Recent Developments in the Conservation of Parchment Manuscripts. The American Institute for Conservation Book and Paper Group Annual. 15, 14-15. Available http://aic.stanford.edu/sg/bpg/annual/v15/bp15-14.html
Mowery, J. Franklin. (1991). The Conservation of a Thirteenth Century Armenian Manuscript. The American Institute for Conservation Book and Paper Group Annual. 10, 10-12. Available http://aic.stanford.edu/sg/bpg/annual/v10/bp10-12.html
1 comment:
This is very interesting information on repairing parchment. It's wonderful to know that parchment can be repaired and preserved for the education and enjoyment of future generations. I also enjoyed the photos.
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