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Conservation of parchment

Introduction

According to René Larsen (Royal Danish Academy of Fine Arts, Schools of Architecture, Design and Conservation in Copenhagen), the results of the IDAP-project (EU FP5 program in 2001–2005) show that the conservation methods of the last 30 years have done more harm than good to parchment. To date, the memory institutions of dozens of European countries have reviewed the current conservation practices Many of current principles have been invalidated and the methodology and preservation rules for the conservation of parchment have been fundamentally changed. First and foremost, the bases for the new approach to the preservation of parchment are the systematic diagnoses of the state of the collections, the need to prioritize the work when organizing conservation, and the selection of conservation methodologies based on the condition of the parchment and research results. René Larsen, who presented a summary regarding the conservation of parchment and training of conservators on 21 September at the Science and Cultural Heritage in European Training in Rome in 2011, affirmed the need for the faster adoption of scientific approaches to the conservation of parchment. Despite the introduction of the results of the IDAP-project at seminars in recent years, and the availability of new diagnostic tools, the research results often are slow to impact the practical, handicraft-based everyday work of conservation at memory institutions. Training sessions for conservators financed by the European Union have been taking place since 2005. The most recent took place in 2012 (project MEMORY). Based on the fact the previous methods for the treatment of parchment (in use before 2000) may have harmed the parchment, it is recommended that all currently conserved parchment documents be carefully re-examined and their status assessed. In order to obtain an overview of the methods for treating parchment, the conservation practices in the Western counties and Estonia will be examined separately. The conservation of parchment in various memory institutions in Estonia between 1960 and 2007 has been summarized and, in addition, the conservation methods used in the course of the 2010–2012 parchment digitization project at the Tallinn City Archive have been described. A good overview of the conservation of parchment in Russia until 1990 is provided by the publications of Estonian conservators (1, 3). From these publications it becomes clear that the principles related to the conservation of parchment in the Western countries and Russia were quite different. The abundance of the materials, tools and treatment methods used for the conservation of parchment during the last 50 years or more is noteworthy. During the early years in the 1960s, parchment conservation in Estonia was strongly impacted by the Russian school. However, the latter differed significantly from the principles adhered to in the Western countries. The chemical treatment of parchment was employed significantly less in the Western countries. The early practical experience of the Western countries was also used in Estonia. Thus, for instance, the oldest known recipe used in Estonia dates back to 1898 (F. G. Lonchamp, Tanniinilahuse retsept pärgamentkäsikirjade elustamiseks. V. Nagel, 1976, pp 129-150).

On conservation abroad

Overview of parchment conservation abroad

The following parchment treatment methods, based on the needs and status of the parchment, were used most frequently during the 1970s in the Western countries.

  1. Cleaning. Removal of biological dirt, surface dirt, glue residue and other build-up from the parchment surface.
  2. Removal of previous mendings.
  3. Consolidation of degraded parchment.
  4. Solvent treatments.
  5. Bleaching.
  6. Humidification.
  7. Lubrication of horny, desiccated parchment softening and straightening).
  8. Local treatment.
  9. Flattening, drying.
  10. Mending.
  11. Lining, lamination of the parchment.
  12. Tensioning at the edges.
  13. Flattening under pressure.
  14. Desinfection.

Based on this classification of treatment methods (AIC Wiki), each operation could, in turn, include up to ten different treatment options. Characteristic of all the parchment treatment methods was that fact that a lot of wet processing and many different chemical solutions were used in the conservation. At that time, the selection of treatment methods was based on the principle that, after the conservation, the surface of the parchment should be light, without significant stains, and as flat as possible. In order to achieve a flat parchment surface, various water solutions were used and the parchment was kept under pressure between wet compresses for extended periods. In the 1990s, the conservation of parchment in the Western countries underwent great changes: dry processing method came into favor; the use of water solutions was limited; and such activities as bleaching, and removing stains were abandoned. New materials (Wishab Dry Cleaning Sponge, Goretex, Hollytex, Sympatex, Mylar etc.) enabled parchment to be cleaned and conserved with the least amount of damage. In the 21st century, the principle for the preservation of parchment is to minimally conserve the parchment. Often the activities are limited to preparing the parchment for digitization. In these cases, the surface is dry cleaned, local breaking points are stretched, and various methods are employed to ensure the integrity of the parchment (the ink is fixed, parchment is supported for handling, and if necessary repaired). More resources are invested in the documentation of the item’s condition and the the conservation process. In this way, the resources spent on digitization benefit both the users, and ensure the better preservation of the originals.  Today’s digitization techniques enable high-quality images (backup copies) to be created even if it is not possible to totally flatten the parchment. Digitization makes it possible to sharpen the image, and to change the scanning time, so that the depth of field of setting is between 2.5–3 cm. However, this means that even if the evenness of the parchment in one document during scanning differs almost 3 cm, it is still possible to get a digital image with high resolution (6.3 line/mm) and good text readability. Literature and internet sources: Christopher C. Wood. Conservation Treatments for Parchment Documents. Journal of the Society of Archivists, Volume 16, Issue 2, 1995. Conservation of Leather and Related Materials. M. Kite, R. Thomson. Oxford, 2006. AIC Wiki, 24.03.2016 Abigail B. Quandt. Recent Developments in the Conservation of Parchment Manuscripts, The American Institute for Conservation, vol. 15, 1996. http://cool.conservation-us.org/coolaic/sg/bpg/annual/v15/bp15-14.html, 29.03.2016

On conservation in Estonia

Survey of the conservation of parchment in Estonia

The treatment methods for parchment were defined similarly to those in the Western countries. However, during specific periods, the techniques used in the case of each treatment method could be quite different from those used in the Western countries. By 1969, there were 14 popular treatment methods used for the conservation of parchment in Estonia (see the list below and table 1).  The selection of the treatment methods depends on the condition of the parchment.

  1. Cleaning, wet and dry cleaning
  2. Removal of previous mendings
  3. Consolidation of degraded parchment
  4. Solvent treatments
  5. Bleaching
  6. Humidification
  7. Lubrication of horny, desiccated parchment softening and straightening)
  8. Local treatment
  9. Flattening, tensioning, drying
  10. Mending
  11. Lining the parchment
  12. Flattening
  13. Pressing
  14. Disinfection.

The survey of the treatment methods used by various Estonian institutions is presented as a chart. The small crosses in the chart show which treatment methods (of the fourteen listed above) were used in the referred sources. The explanatory column includes details based on the original sources.

Table 1. Overview of the treatment methods used on parchment in Estonia

treatment methods

Ref.,

year

 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Description of the treatments
1, 1969 + + + + + + + + Cleaning: distilled water (text fixed in advance in the following solution: 13–14ml ПФЭ 2/10 in 100ml ethyl alcohol), ethyl alcohol, 10% urea solution. Softening: lanolin emulsion, 10% urea and ethyl alcohol solution, 2% spermaceti emulsion, egg emulsion. 24 hours in a press between paraffin papers and 7–10 days between blotting papers. A rubber roller was also used for flattening and tensioning with the help of clamps. Repair: long-fibred paper tinted with coffee and tea, wheat flour paste, ПФЭ- 2/10, ПФЭ (methyl polyamide adhesive), patches dried in the press.
2, 1971 + + + Physical cleaning in urea solution, lanolin emulsion

Document from the Estonian Literary Museum, F118, M18:1, 18th cent., 1 side
3, 1976 + + + Physical cleaning, ethyl alcohol and spermaceti solution

Documents from the State Central History Archive, f. 2069, nim. 2, s. 1008, 1598; f. 2069, nim. 1, s. 56, 1681.
3, 1976 + + + + Physical cleaning, semi-dry cleaning: water, ethyl alcohol. Softening 10% urea solution.
4, 1976 + + + + + + + + + Tartu State University Library (TÜRmk.) treatment methods: cleaning with a soft rubber or fresh breadcrumbs, fixing the text with 96% ethyl alcohol, fixing the colors with gelatin or 3% methyl polyamide solution, removal of stains with oxalic acid, softening with 5%, 10% urea solution, 2% spermaceti solution, drying on a frame while stretching it with weights (if the parchment is intact) for 1 to 2 days, and thereafter, between blotting papers in a press (7-10 days).
5, 1989 + + + + + + + Faber-Castell eraser, 95–100% water bath steam. Hand roller, smoother, self-flattening, small pieces of skin and bladder for repairs. 2–45% solution of cedar oil and aqueous ethyl alcohol, lanolin cream (white spirit, petroleum jelly, glycerin).
6, 1990

7, 1992

 + + 3% solution of cedar oil and ethanol

Document from the History Museum, AM 115-II/32 certificate of a cook’s apprentice 1770.
8, 1997 + + + + + + + The following treatment was used by EK Kanuti.  Dry/wet cleaning: eraser, rubber cleaning powder, breadcrumbs, distilled water +alcohol, enzymes. Fixing:1–5% Paraloid B-72 (later removed with acetone). Moisture chamber, wet filter paper, self-flattening with the help of clamps. Washi (Japanese paper) covered with Plextol polymer was used to strengthen the repairs. Washi (Japanese paper) and parchment was used to mend the holes with 12% gelatin glue.

Documents from the History Museum: EAM 115.1.62, 16th cent., EAM 115.1.63, 16th cent.
10, 2006 +

+

 +

+

 + + +

+

 + + + + Between 1964 and 1989 the following treatments were used in the State Central History Archive. Wet cleaning with water. Dried in a press between papers/felt. For softening, a 10% solution of urea (H2NCONH2) used or a lanolin emulsion that contained lanolin, glycerin, children’s soap water or ethanol

Between 2000 and 2006, the condition of 400 History Museum documents was determined and the documents were conserved.

Dry cleaning: microfiber cloth, latex rubber and brush.  The local breaking points were moistened with 80% isopropanol and water solution. Dried between blotting paper, under light pressure. Moistening of the entire surface with 80% isopropanol between Goretex. Dried by flattening on a frame. In the case of serious deformation, a softening solution was used, which included: 48% water, 48% ethanol, 2% urea and 2% sodium chloride. The patches were glued with 12% gelatin glue.
11, 2011 + + + In 2006 and 2007, the following treatments were used in the Tallinn University Library:  eraser, 50% ethanol and water solution. Kept for four hours in a moisture chamber. The following was used for softening: lanolin cream (components: 200 ml distilled water, 4 g natural soap, 16 ml glycerin,10 g lanolin, 20–30 ml ethanol).
CDC Kanut conservation protocols 1987-1998 + + + + + + + + + + 12 documents from the History Museum (AM).

Both dry and wet (with water) cleaning was used. Stains eliminated with 5% oxalic acid. Moistening in a climate chamber between wet blotting papers. Disinfection with formalin in an autoclave. Stretching on a frame and pressing. Polymer patches covered with Washi (Japanese paper) and parchment. Glue: 12% gelatin solution. Softened with a cedar oil and ethanol CDC
 CDC Kanut conservation protocols 1998-2007 + + + + + + + + + + 86 parchments AM, TÜRmk, Tallinn City Archive (TLA).

Cleaning with a Classical Sponge, formerly Wishab   and Dry Cleaning Sponge, distilled water with enzymes (saliva) and or an orange oil and water solution, 50% ethanol solution. Colors fixed with a 2% to 5% Klucel G solution in ethanol. Moistening in a water compress or 80% isopropanol solution between Sympatex or Goretex in a compress. Softening with an 80% isopropanol solution. Stretching on or on a vacuum table with Bulldog clips.
Tallinn City Archive

Starting in 2001

 + + + + + + + + + + Cleaning: Wishab and sponge, Smoke& Dust sponge, eraser, distilled water, enzymes (saliva), 30-50% ethanol solution.

For fixing the text and colors: with 5% Klucel G solution in ethanol. Softening 80% ethanol solution. Moistening: Sympatex packet. Stretching: on penoplast with Bulldog clips. Repairs: Washi (Japanese paper), Klucel G.
Summary

Summary of parchment conservation in Estonia

Based on the history of Estonian conservation included in the survey (9), it can be said that that, starting in the second half of the 1950s, the interest in the restoration of books, including parchment, increased.  The first position of restorer (Liidia Noodla) was established at the University of Tartu Library in 1957.

Based on the data included in the articles (3) by L. Noodla and V. Nagel in 1976, by the early 1970s, 39 parchment folios and 34 parchment manuscripts had been restored and conserved at the University of Tartu Library.

Between 1960 and 1990, Estonian restorers basically acquired their skills for working with parchment in Moscow, Leningrad and Vilnius (at the USSR Central Library, the Document Conservation and Restoration Laboratory of the Leningrad Academy of Sciences, the Saltykov-Shchedrin State Public Library, and University of Vilnius Library).

During this period, the Russian school of parchment conservation has a big impact on the Estonian conservators (1,4). To what extent these skills were employed in various Estonian institutions is difficult to determine, because the restoration protocols from that time are incomplete and too generalized. Some of the acquired know-how that was adopted in Estonia and, decades later, these practical skills were still being used by conservators. Some of these treatments were even being used during this century (for instance, the use of lanolin cream for softening, and drying in a press).

A summary of almost twenty years of practices related to the conservation of parchment in Estonia, along with the recipes used for conservation, are presented in methodical instructions (13).

The most important of the skills acquired in Russia, which were used by Estonian conservators are related to the following parchment treatment methods:

  • Cleaning with soft rubber or fresh bread crumbs.
  • Moistening with a mixture of 10% urea solution and lanolin emulsion, and moistening with water in a press between filter papers.
  • Strengthening with gelatin glue.
  • Softening with 5% and 10% urea solution, 2% spermaceti emulsion, egg emulsion (components: beer wort, wet ice, cooking salt, olive oil, egg yolk, thymol).
  • Fixing of colors with gelatin or 3% methyl polyamide solution in a urea solution
  • Fixing of text with 96% ethyl alcohol or ПФЭ 2/10 (20-30% spirit solution of polyamide adhesive).
  • Repairing with long-fiber paper, light condenser paper, parchment and skin. For gluing, wheat flour paste, parchment glue (components: ПВС 7%: polyvinyl alcohol, water, glycerin) or methyl polyamide adhesive (ПФЭ).
  • The treatment of manuscripts with faded texts with weak tannin solution.
  • The removal of stains with oxalic acid.
  • Parchment was dampened with ethyl alcohol and water solution and flattened between glass plates under pressure
  • Drying on a frame while stretching with weights (done if the parchment is intact) for 1 to 2 days and thereafter in a press between blotting papers (7 to 10 days).

Starting in the second half of the 1990s, Estonian conservators starting attending parchment conservation training courses in Western Europe: Reet Brido in Finland in 1996 (in Vantaa the course was taught by D. Collins from Camberwell College of Arts), Eve Keedus in 2000, 2005, and 2013 in Denmark; Sille Feldberg in 2011–2012 in Horn, Austria at courses organized by Jiri Vnoucek  and Rene Larssen, see the sample preparation of parchment (PDF) and training program.

Thanks to the knowledge acquired at the training courses, the methods for treating parchment changed: dry treatments started to be preferred for cleaning; the amount of water in water solutions was reduced to a minimum; localized treatments started to be preferred over treatment with solutions covering the entire surface; drying in presses was abandoned and the self-stretching of parchment preferred. New materials (Goretex, Hollytex, Sympatex, Mylar, etc.) enabled parchment to be conserved while causing less damage (8,10).

The condition of parchment was determined using a specific methodology for the first time at the History Archive, and based on the results, the durability of the entire collection of parchment documents was analyzed. The entire collection was packed into archival boxes and stored according to EVS- ISO 112799: 2003 requirements (10).

The results of the European parchment preservation development project (IDAP project, EU FP5 program in 2001- 2005) and the training courses that introduced the results helped to better understand the properties of parchment, the limited opportunities for conserving historical parchment documents and the rules for preservation. As the result of the development project, the methodology for determining and documenting the condition of parchment has changed. The methodological recommendations for determining and document the condition of parchment, as well as conserving and preserving it have been published between 2005 and 2012 in several IDAP project publications.