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PARCHMENT

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|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|63|Parchment Paper - Vegetable or imitation parchment is made by passing unsized paper through a bath of sulphuric acid, followed by thorough washing in water, immersion in dilute ammonia to neutralize the acid, and sometimes a coating or bath of glycerine or glucose, followed by drying. It is a strong, durable, translucent paper with a good writing surface and is often used instead of genuine parchment (made from animal skin) for legal documents, certificates, and souvenir facsimiles.|Question: How dissimilar is it from true parchment?|

|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|78|Vellum and Parchment - Vellum and parchment were used extensively in the Middle Ages as writing surfaces for manuscripts; vellum also has been used since this period as a covering material in bookbinding. Traditionally, true vellum is the unsplit skin of a young calf, while parchment is made from split sheepskin.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|79|THe method of producing both is the same, however. Skins are preserved by soaking them in a lime (strong alkali) solution, cleaned and scraped to remove the hair, and dried under tension on a wooden frame. While still under tension, skins are smoothed or finished by shaving them with a knife and rubbing them with pumice.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|79|Today, both vellum and parchment are made from the skin of any small animal, such as calf, sheep, or goat. Both skins are strong and long-lasting (due in part to the lime, which is not removed during processing); ||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|79|...they also are very reactive to changes in the moisture level. They will cockle (contract to form wrinkles and puckers) when dampened and allowed to dry without restraint, and many books covered in vellum have warped boards as a result of changes in the relative humidity.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|79|Vellum and parchment are not in common use today except by artists and book conservators (although parchment is occasionally used for legal documents and certificates).||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|79|These skins are found, however, in archival collections that contain early manuscripts and legal documents, as well as in college and university archives that have parchment diplomas (the proverbial sheepskin).||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|79|Both skins appear smooth and hard; depending on thickness, they may be translucent or opaque, with a color ranging from creamy white to ecru.  ||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|79|Vellum can be stained any color, but usually is not; many vellum skins have faint vein and hair markings.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|79|It is often difficult to differentiate between parchment and vellum, and //parchment// is the term often used generically to refer to either material. What is most important in an archival context is that recognize that a material is //either// parchment or vellum, as their handling and treatment needs, are the same.||

|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|95|These organic substances are composed of complex polymer molecules that undergo a natural aging process as the molecular chains break down, or depolymerize, resulting in deterioration. Natural aging is a slow and inevitable process. While measures can be taken to slow natural aging by providing a sympathetic environment, it is impossible to halt this process altogether. While measures can be taken to slow natural aging by providing a sympathetic environment, it is impossible to halt this process altogether. The rate of deterioration depends on the inherent chemical stability of the material, in combination with external influences such as the environment and storage conditions.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|95|Some organic materials, the chemical makeup of which may be inherently unstable, will age more quickly than other stored in exactly the same environment.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|95|Poor handling procedures can also result in physical damage to records.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|95|Inorganic materials, which are generally defined as chemical compounds that are largely outside the realm of living or once-living organisms (such as minerals and metals), are not subject to the same aging or deterioration processes as organic materials||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|95-96|Environmental factors that can hasten the deterioration of paper and other materials include high temperature, elevated relative humidity, light, pollution, and biological agents. Independently, each of these factors, if uncontrolled, can cause specific types of damage to record materials, but they also have distinct cumulative relationships to one another.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|96|For example, the rate of many chemical reactions depends on both temperature and moisture content. Thus, the combination of high temperature and high humidity accelerates the decomposition of alum-rosin sizing to generate sulphuric acid in paper.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|96|Also, it has been demonstrated that the two primary chemical reactions that degrade paper - hydrolysis and oxidation - accelerate one another. ||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|96|Other actions that speed up the damage to and loss of archival materials include extensive  handling and improper storage and care, as well as disasters, which can cause untold manage or utterly destroy collections in a brief span of time. (Tom Lindstrom, "'Slow Fires' - Its Paper Chemistry, Physics, and Biology," in Paper Preservation: Current Issues and Recent Developments, ed. Philip Lunder (Atlanta, GA: TAPPE Press, 1990), 75.||

|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|96-97|Temperature and relative humidity both a great impact on the rate of deterioration of paper and other record materials. High temperatures speed up chemical reactions. For every 18°F (7.7°C) increase in temperature, chemical activity in most substances approximately doubles. It has been estimated that the useful life of paper is cut approximately in half with every 10°F (12°C) increase in temperature. Conversely, wither every 10°F (12°C) decrease, the expected life of paper is effectively doubled.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|97|Relative humidity is defined as the amount of water vapor in a volume of air, expressed as a percentage of the maximum amount that the air could hold at the same temperature. The warmer the air, the more water vapor it is capable of holding. Thus, the relative humidity decreases as the temperature increase, assuming no moisture is added.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|97|The amount of moisture in the air is important because of its relationship to chemical activity and also because of the physical effect it has on organic materials. As stated above, many of the harmful chemical reactions that speed up the deterioration of paper and other materials are both temperature- and water-dependent. Hight humidity accelerates such chemical reactions as acid hydrolysis, which breaks down the molecular structure of the paper.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|97|Conditions of high humidity combined with high temperatures, in addition to accelerating chemical acidity, also encourage the growth of mold and mildew and increase the likelihood of insect infestation.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|97|Under conditions of extremely high humidity, water-soluble inks can offset and coated papers can stick together.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|97|Relative humidity that is too low causes materials to become dry and brittle and can lead them to contract and shrink, resulting in shearing and lifting of laminate structures, including those of some photographic materials. Desiccated paper can break and crumble as it is handled and flexed, and the covering materials or books (such as vellum) can shrink, causing boards to warp. The level of relative humidity that promotes optimum preservation is different for different organic materials.|VELLUM|
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|98|Both high relative humidity and exposure to localized moisture can cause parchment sheets to stick together and manuscript ink to bleed, as seen here. [image 4-2]||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|98|As the temperature changes, the relative humidity fluctuates. This fluctuation, or cycling, can be quite drastic, with as much as a 20 to 30 percent change in relative humidity in a 12- to 48-hour period; the rate of change can be even faster during a disaster such as a water or steam leak. Paper, vellum, and parchment are all hygroscopic materials, which means that their moisture content changes in relation to the amount of water in the surrounding air. (Hygroscopic materials take up moisture much more quickly than they release it, which has implications for emergencies involving water.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|98|Thus, wide swings in temperature (and therefore in relative humidity) can be very damaging, as such materials expand and contract in response to changes in the moisture level). While the movement of actual paper fibers is not visible to the naked eye, the resulting internal stress and dimensional instability is very damaging to paper records over time.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|99|Structural composition and format is important in this context. ||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|99|Also, materials that are partially restrained and cannot move freely - such as the parchment that is drummed around a stretcher - ultimately will suffer more damage in response to changing relative humidity than will loose sheets. [Footnote 3: For example, parchment that is adhesively attached to a mount around its edges will contract as the relative humidity lowers. Where the parchment is restrained at its edges, it is constrained and cannot move and thus will tend to break at the interface between the adhesive contact and the remainder of the sheet that is able to move in response to moisture changes. To deal with this problem, string-type mounts were devised for parchment that involves securing the parchment to its mount by a border or small strips of Japanese paper that is weaker than the parchment. Thus, if relatively humidity fluctuates and the parchment contracts, the paper, rather than the parchment, will give way and tear.||

|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|99|Pllutants in the air can initiate or hasten the degradation of archival materials. Gaseous pollutant includes ozone, sulfur dioxide, nitrogen dioxide, and hydrogen sulfide, which are products of combustion and other chemical reactions. ||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|100|Ozone, another gaseous pollutant, is a strong oxidizing agent that causes severe damage to organic materials. ||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|100|Other internal sources of gaseous pollutant that must be controlled include smoking, cooking, and off-gassing from unstable materials ( for example, collection items such as cellulose nitrate film as well as some paint finishes in storage areas). Poor-quality paper and paperboard housings also give off a wide range of compounds as they degrade, including acetic acid.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|100|Dirt, dust, soot (carbon), tar, and other solid particles can damage archival material through abrasive action. In addition, dirt and other solid particles may be acidic or otherwise contaminated or may absorb acidic gaseous pollutant,s which they then deposit on collection materials. As the particulates absorb moisture, they become sites for harmful chemical reactions. ||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|100|Dirt and dust, when viewed through a microscope, can appear very menacing, with sharp cutting edges. In the presence of moisture, direct and pollen can cause permanent stains, and skin oils and perspiration, as well as fingerprints, can also set dirt. Oily soot is especially disfiguring and difficult to remove. ||

|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|101|LIght, or radiant energy of a particular wavelength, also affects the longevity of collection materials. All organic materials, including paper, leather, textiles, and pigments, are susceptibles to photochemical damage at a particular trigger point. For some extremely sensitive materials, this might occur as both visible and ultraviolet radiation are absorbed, while more stable materials might be primarily susceptible to ultra-violet radiation.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|101|Light has a bleaching action it can cause some papers to whiten and can cause colored papers and inks to fade. ||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|102|All light is potentially damaging, but ultraviolet radiation, which we cannot see, is the most active and thus has the greatest potential to cause photochemical deterioration. ||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|103|Light damage is cumulative; the amount of damage depends upon wavelength (i.e., near-ultraviolet, violet, blue, etc.) and the length and intensity of exposure. Thus, brief exposure under relatively high intensity can be just as damaging as extended exposure to low intensity...Chemical reactions initiated by exposure to light continue even after the light source is removed and materials are put into dark storage.||

|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|103|Biological organisms that can damage archival materials include fungi (mold and mildew), insects, rodents, and birds. Mold spores are always present in the air and will grow whenever environmental conditions are favorable...Warm, humid conditions (generally above 75°F (24°C), with a relative humidity above 60 or 65 percent), darkness - or light, depending on the species - and little air circulation encourages the growth and mold.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|103|The presence of water, however, appears to be the primary factor in encouraging mold growth; nutrients are secondary. [note 5: Mary-Lou Florian, Heritage Eaters: Insects and Fungi in Heritage Collections (London: Maney Publishing, 1997.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|104|Insects, rodents, and other pests feed on cellulose as well as on other organic substances found in collections, such as paste, glue, relative sizing, leather, and book both. ||

|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|105-106|Unfortunately, people pose the most constant threats to archival collections. Improper handling, whether imposed by archival staff or researchers, intentional or note, results in the same damage and potential loss of records and information.||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|106|Poor handling includes a wide range of actions, such as careless or rough interactions with collection materials, damaging copying practices, improper transport, and lack of protective housing. The list is extensive. While much damage results from carelessness, abuse also includes such blatant acts as mutilation, vandalism, and theft.||

|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists|298|The following materials represent a high priority for attention following a water-related event: parchment documents, which can distort and cockle when exposed to moisture and shrink if permitted to dry without restraint||

|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists||||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists||||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists||||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists||||
|Ritzenthaler, M. L. (2010). Preserving archives & manuscripts, 2 ed. Chicago, IL: Society of American Archivists||||