Atlas of the characteristics and damages of parchment

Currently, there are no consistent position regarding the definition of damages, usually the basis is established by the purpose for determining the damages. In most cases, it is necessary to assess the condition of the object based on the types of damages and their extent. Because, as a rule, damages worsen the condition of the object, important concepts related to the definition of damages are the original state and the damaged condition. When visually determining the damage, a comparison is made with the original state of the object and its damaged state. It is assumed that initially the object was physically intact and the damage that has worsened the condition of the parchment has become visually discernible as the result of subsequent handling and storage. The concept of the original state is usually hypothetical. Therefore, the determination of the damage is always related to a description of the extent to which the characteristics have changed and the hypothetical comparison of the relevant conditions. See the description of damage by J. Ashley-Smith and Eric Dirix, CeROArt, 08.09.2017.

In the atlas of parchment damages, the following definition is used: damage is a change in the object that has a negative impact on the condition and value of the object, partially or as a whole (K. Konsa. Raamatukahjustuste atlas, 23.03.2016). Based thereon, the changes that occur in the course of the natural aging of a material are also considered to be damage.

The goal of this atlas is to help in documenting the changes that have occurred in historical parchment as a writing material and diagnosing the condition of the parchment in the course determining the damage visually. Depending on how extensively damaged the surface of the parchment is, the condition is defined according to the degree of damage that has occurred. Thus, for instance, the frequency of glass-like layer and physical damage is divided into three categories. At the same time, in the case of some damage, i.e. the damage caused by the processing of the parchment or various types of deformation, the damage is divided into two categories: occurs/does not occur.

There is also damage in the case of which a visual determination may turn out to be misleadingly subjective or methodologically complicated. Such descriptions of damage have been knowingly avoided in this atlas. For instance, the darkening and yellowing of parchment. In the case of parchment, the traditional methods that have been developed for testing localized surfaces in order to assess yellowing/whitening (i.e. color catalogs, and photo spectroscopy) do not always provide an unambiguous, repeatable result that can be applied to the entire document. The reason is the uneven darkening and yellowing of entire surface of the document, especially in the case of those documents in which significantly differing color changes occur on the recto and verso sides. In addition, the determination of this damage is made questionable because information is lacking regarding the color of the parchment when the document was in its original state.

Ill.1. Pärgamendi kiulise hierharhilise struktuuri algosaks on tropokollageeni molekulid (a). Kollageeni kui valgu molekulaarne struktuur tekib kolme polüpeptiidide ahela (s.o peptiidsidemete abil üksteisega seotud aminohapete) erilisel kokkupakkimisel keerdunud vasakukäelisteks spiraalideks e. mikrofibrillideks, (b). Kindla perioodilisusega korduvad ülekandealad on kiudude uurimisel elektromikroskoobiga tumedate triipudena hästi nähtavad (c). Mikrofibrillidest moodustuvad kollageeni kiud (d). Allikas: https://www.researchgate.net/figure/273149156_fig1_Figure-1-Hierarchical-structure-of-collagen-a-tropocollagen-molecul</ br>
The initial part of the fibrous hierarchical structure of parchment is tropocollagen molecules (a). The molecular structure of collagen as a protein is formed by the special packing of three polypeptide chains (i.e. amino acids connected to each other by peptide bonds) into twisted left-handed spirals e. into microfibrils, (b). Repeated transmission areas with a definite periodicity are clearly visible as dark stripes when examining the fibers with an electromicroscope (c). Collagen fibers (d) are formed from microfibrils. — Ill.1. Pärgamendi kiulise hierharhilise struktuuri algosaks on tropokollageeni molekulid (a). Kollageeni kui valgu molekulaarne struktuur tekib kolme polüpeptiidide ahela (s.o peptiidsidemete abil üksteisega seotud aminohapete) erilisel kokkupakkimisel keerdunud vasakukäelisteks spiraalideks e. mikrofibrillideks, (b). Kindla perioodilisusega korduvad ülekandealad on kiudude uurimisel elektromikroskoobiga tumedate triipudena hästi nähtavad (c). Mikrofibrillidest moodustuvad kollageeni kiud (d). Allikas: https://www.researchgate.net/figure/273149156_fig1_Figure-1-Hierarchical-structure-of-collagen-a-tropocollagen-molecul The initial part of the fibrous hierarchical structure of parchment is tropocollagen molecules (a). The molecular structure of collagen as a protein is formed by the special packing of three polypeptide chains (i.e. amino acids connected to each other by peptide bonds) into twisted left-handed spirals e. into microfibrils, (b). Repeated transmission areas with a definite periodicity are clearly visible as dark stripes when examining the fibers with an electromicroscope (c). Collagen fibers (d) are formed from microfibrils.

Ill. 2.Pärgamendi kiuline struktuur on korraldatud kiukimpudena, fibrillidena (diameetriga 250–500 nm), mis on moodustunud mikrofibrillidest vesiniksidemete, kovalentsete sidemete ja soolade abil .
Mikrofibrillidest moodustub fibrill ning fibrillidest omakorda kollageenikiud ja -kiudude kimbud. </ br>
The fibrous structure of parchment is organized as fiber bundles, fibrils (250–500 nm in diameter) formed from microfibrils by hydrogen bonds, covalent bonds and salts.
Microfibrils form a fibril, and fibrils, in turn, form collagen fibers and bundles of collagen fibers. — Ill. 2.Pärgamendi kiuline struktuur on korraldatud kiukimpudena, fibrillidena (diameetriga 250–500 nm), mis on moodustunud mikrofibrillidest vesiniksidemete, kovalentsete sidemete ja soolade abil . Mikrofibrillidest moodustub fibrill ning fibrillidest omakorda kollageenikiud ja -kiudude kimbud. The fibrous structure of parchment is organized as fiber bundles, fibrils (250–500 nm in diameter) formed from microfibrils by hydrogen bonds, covalent bonds and salts. Microfibrils form a fibril, and fibrils, in turn, form collagen fibers and bundles of collagen fibers.

Ill. 3. Rasvade eemaldamine on aga raskendatud juhul, kui ei eemaldata täielikult derma pindmist kihti (ingl grain layer) koos seda kihti läbivate karvaaukudega, mis moodustavad pinna lähedases alas raskesti puhastatavaid süvendeid. Foto on tehtud Tallinna tehnikaülikooli materjaliuuringute teaduskeskuses.</ br>
However, the removal of fats is more difficult if the surface layer of the dermis (English grain layer) is not completely removed along with the hair holes passing through this layer, which form pits that are difficult to clean in the area near the surface. The photo was taken at the Materials Research Center of Tallinn University of Technology. — Ill. 3. Rasvade eemaldamine on aga raskendatud juhul, kui ei eemaldata täielikult derma pindmist kihti (ingl grain layer) koos seda kihti läbivate karvaaukudega, mis moodustavad pinna lähedases alas raskesti puhastatavaid süvendeid. Foto on tehtud Tallinna tehnikaülikooli materjaliuuringute teaduskeskuses. However, the removal of fats is more difficult if the surface layer of the dermis (English grain layer) is not completely removed along with the hair holes passing through this layer, which form pits that are difficult to clean in the area near the surface. The photo was taken at the Materials Research Center of Tallinn University of Technology.

Ill.4. Karvaaugumuster pargitud vaskanaha pinnal. (Codex Sinaticus, 24.03.2016 ).</ br>
Hair hole pattern on the surface of tanned copper skin. — Ill.4. Karvaaugumuster pargitud vaskanaha pinnal. (Codex Sinaticus, 24.03.2016 ). Hair hole pattern on the surface of tanned copper skin.

Ill.4a. Karvaaugu muster vasikanahast pärgamendi pinnal erineb karvaaugu mustrist pargitud vasikanaha pinnal, vt Ill.4. (Codex Sinaticus, 24.03.2016 ).</ br>
The hair-hole pattern on the surface of calfskin parchment is different from the hair-hole pattern on the surface of tanned calfskin, see Ill.4. — Ill.4a. Karvaaugu muster vasikanahast pärgamendi pinnal erineb karvaaugu mustrist pargitud vasikanaha pinnal, vt Ill.4. (Codex Sinaticus, 24.03.2016 ). The hair-hole pattern on the surface of calfskin parchment is different from the hair-hole pattern on the surface of tanned calfskin, see Ill.4.

Ill.5a. Degradeerunud kitsenahast pärgamendi karvaaukude muster erineb pargitud kitsenaha karvaaugu mustrist vt Ill.5. (Codex Sinaticus, 24.03.2016 ).</ br>
The hair-hole pattern of degraded goatskin parchment is different from the hair-hole pattern of tanned goatskin. — Ill.5a. Degradeerunud kitsenahast pärgamendi karvaaukude muster erineb pargitud kitsenaha karvaaugu mustrist vt Ill.5. (Codex Sinaticus, 24.03.2016 ). The hair-hole pattern of degraded goatskin parchment is different from the hair-hole pattern of tanned goatskin.

Ill.5. Pargitud kitsenahk. Karvaugu muster pargitud kitsenaha pinnal. (Codex Sinaticus, 24.03.2016 ).</ br>
Tanned goatskin. Hair hole pattern on the surface of tanned goatskin. — Ill.5. Pargitud kitsenahk. Karvaugu muster pargitud kitsenaha pinnal. (Codex Sinaticus, 24.03.2016 ). Tanned goatskin. Hair hole pattern on the surface of tanned goatskin.

Ill. 6. Ühe imetaja naha pinnalaotusel on lokaalselt erinev nii naha kiuline struktuur kui ka kiudude orienteeritus. </ br>
Both the fibrous structure of the skin and the orientation of the fibers are locally different on the surface of the skin of one mammal. — Ill. 6. Ühe imetaja naha pinnalaotusel on lokaalselt erinev nii naha kiuline struktuur kui ka kiudude orienteeritus. Both the fibrous structure of the skin and the orientation of the fibers are locally different on the surface of the skin of one mammal.

Thus, just as it is difficult to define the general concept of damage, in the case of various types of damage, it is also difficult to present it in a visually unambiguous way. The various types of damage may often be related as far as the reason for its development and its impact on the condition of the document. If, for instance in the case of a large-format document, not only the center section of the skin was used, but the parchment sheet was cut out of the area along the stomach and around the limbs, various sections of the parchment will have very different characteristics (thickness, density, chemical properties). As the parchment starts to age naturally, this will cause various types of deformations to develop throughout the surface of the initial flat material. Such deformations may also cause physical damage to occur (e.g. tears, detachment of the material). At the same time, deformations, similar to the ones described above, may have been caused instead by the improper storage and handling of the parchment.

In the atlas, the damage and characteristics are classified according to their recognizable causes. Therefore, in order to avoid mistakes, the popular terms for identifying stains as damage are not used: water(moisture) stain, grease stain, etc. Since determining the exact causes of stains would require additional research about the origin of stains, the atlas allows only one main type of stain to be defined by visual observation: C6.3 Stains. The only differentiated sub-type is the stains caused by handling, including fingerprints (C6.3.1) and ink stains (C6.3.2).

The atlas, in order to avoid mistakes, also does not use the damage classification that has been used to date, i.e. physical, chemical, biological, and environmentally-caused damage, which was used in the atlas of paper damage compiled by the National Library of Estonia in 2008 and the atlases compiled by the National Archives of the Netherlands (23.03.2016). This classification has been avoided because the reasons for chemical, biological and environmentally-caused damage are often so closely related that their impact is difficult to distinguish visually.

The atlas of damage describes 50 parchment damages and properties that are visually discernible parchment damages and have a definite terminology, and which can significantly impact the condition of parchment. The categories of damages and properties and the list of categories along with the relevant terms and explanatory texts can be found in the register of parchment damages and properties.

In order to simplify the identification of damages, the following structure is used in the atlas:

Structure of the atlas

Illustration explaining the connections in the atlas of parchment attributes and damage.

This structure enables short codes to be used to define all the damages and properties.

For example, the code for ‘ink corrosion’ in the atlas is C6.07; the first half of the code (C6) helps to diagnose the possible causes of the damage and the second half (07) defines the type of damage along with the term in Estonian and English.

The most important part of the atlas of damages is the visual presentation of the possible specific characteristics of the damages and properties as image files along with a description of the damages, the origin of the document, and the determination of the condition. A general view of and metadata for the document are also added. This information can be presented in short form with the damage and properties code, i.e. encoded.

The coding of the damages and properties helps to present the damages more easily and comprehensively along with additional information on the possible causes.