2.3 PARADIGM SHIFT IN THE ROLE OF ARCHIVISTS AND PRESERVATION MANAGEMENT MANAGEMENT
2.5.3 Restoration and conservation processes
Conservation and restoration are the most central activities of preservation; they are concerned with the physical maintenance and repair of documentary materials (Matthews 1990).
According to Roberts and Etherington (n. d) conservation is a field of knowledge concerned with the coordination and planning for the practical application of the techniques of binding, restoration, paper chemistry, and other material technology, as well as other knowledge pertinent to the preservation of archival resources.
Conservation can be further characterized as both preventive and remedial. Preventive conservation consists of indirect action to retard deterioration and prevent damage by creating conditions optimal for the preservation of materials. On the other side of the coin, there is remedial conservation, which consists mainly of direct action carried out on documents in order to retard further deterioration. It is akin to restoration.
Restoration is the process of returning archival materials as nearly as possible to their original condition. Respecting, as far as possible, the aesthetic, historic and physical integrity of materials is the underlying principle that defines restoration activities. The entire scope of restoration ranges from the repair of a tom leaf, or removal of a simple stain, to the complete rehabilitation of the material including, at times, deacidification, alkaline buffering and resizing (Roberts & Etherington. n. d).
Conservation and restoration hinge upon diagnostic examination. Diagnostic examination encompasses determining the composition and condition of materials; identifying extent and nature of alterations; evaluating the causes of deterioration; and determining the type and extent of treatment needed (Roberts & Etherington. n. d).
The major conservation-restoration processes like deacidification, leaf casting, encapsulation, lamination and providing microenvironments are discussed in the following subsections. This section on conservation and restoration processes concludes by looking at conservation and restoration facilities, which are key to carrying out these interventive processes.
2.5.3.1 Deacidification
As discussed in section 2.5.1 above, acidity is the major cause of the deterioration of non- alkaline permanent paper. While brittle materials could be reformatted for preservation, there is also the troubling question of what to do about the millions of acidic but not yet brittle records and archives inexorably deteriorating in repositories. Deacidification is a tool that many archivists and records managers had anticipated could be used to help combat the serious problem of the acidic archival holdings. William Barrow, the well-known preservation pioneer, was responsible in part for the widespread acceptance of deacidification from the
I 940s through the 1960s in both the library and archives communities (Jones 1999).
Valuable deteriorating documents are deacidified by treating the paper with a mildly alkaline solution (pH< 1 0) that deposits a carbonate salt into the fibre of the paper. By adding 3% by weight of calcium carbonate the deacidification process may extend the life of a document as much as 500 years (Wachter 1989). A simplified deacidification procedure is outlined at Appendix Sixteen.
A number of techniques of deacidification have been developed. They range from item treatment procedures to mass processes. Though mass deacidification procedures are being developed and tested, deacidification in archives is presently at the item level. Most experimental work on mass deacidification has been confined to printed library materials at the exclusion of handwritten manuscripts that are very prevalent in archival collections.
Deacidification methods encompass aqueous (water based), non-aqueous (non-solvent) and vapour phase (Ritzenthaler 1993: 144). Aqueous deacidification involves immersing or brushing affected paper with an alkaline solution or suspension (magnesium bicarbonate is generally regarded as the most effective) until the acidity has been neutralised and the pH value has been raised to between 7.5 and 9.0. After treatment any necessary repair is then undertaken and the paper is re-sized and pressed. Aithough, this method is tried and tested, it may not be safe for materials with water-soluble inks or very fragile documents. It is also a very slow, time consuming and costly process (Swartzburg 1995:140). The Wei T'o system described below is an example of non-aqueous system, except that it is being developed for mass deacidification processes.
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Vapour-phase deacidification employs chemicals in gaseous forms to neutralise the acid; this is potentially easier to use and offers greater productivity than either of the processes described above. Unfortunately, most of the gases, which have been used, are poisonous or otherwise injurious to health and this system has been discontinued (The National Archives Of The Netherlands et al. 2001; Wachter 1989).
The cost and limitations of item-by-item treatment has led to the development of mass treatment procedures. Most of the procedures are still in the experimental or developmental stage. All require expensive plant; some require the use of a vacuum chamber, which may be safe for bound volumes but not always for loose sheets; others use chemicals which require careful handling if they are not to be a threat to health and safety. Most are likely to be cost- effective only where a high volume of work can be foreseen. Examples of mass treatment procedures are the Wei T'o system, the diethyl zinc (DEl) mass deacidification gaseous process and the Bookkeeper® process. Each of the processes is presently briefly discussed.
The Wei T'o non-aqueous book deacidification system was invented by Richard D. Smith and developed by the National Archives in Canada. It is one of the world's leading deacidification systems (Herion 2000:48). The books to be deacidified are soaked in a mixture of freezing substances (frigen) as a transport medium and a deacidification agent magnesium methoxide dissolved in 5% methanol and a chlorofluorohydrocarbon solvent (Grimard 1994:676;
Ritzenthaler 1993: 145; Wachter 1989). Thus far the Wei T' 0 system has been for deacidifying books and not archives (Grimard 1994:677). Its use of alcohol precludes the treatment of documents with certain inks (Grimard 1994:677).
The Library of Congress developed the DEl process in the 1970s under the direction of George Kelly (Harris 2000a:39; Swartzburg 1995:141). Books are placed in a slightly heated vacuum chamber in order to reduce the water content of paper. DEl is then added. DEl reacts with water to form a zinc oxide alkaline buffer. At the end of the procurement effort to obtain mass deacidification services in 1991, the expert advisory panel concluded that the DEl process showed the greatest promise for meeting the Library's technical requirements.
However, it was abandoned because it had some unacceptable flaws such as odour in treated
books, iridescent rings on coated paper and covers and chemical attack on some book covers and adverse effect on adhesives and labels (Harris & Shahani 1994).
The Bookkeeper® process, which was originally developed by the Koppers Company and patented in 1 ~85, is now available from Preservation Technologies (Preservation Technologies 1994). In 1995, after working for over twenty years to solve the problem of acidic paper, the Library of Congress awarded the first contract for mass-deacidification to Preservation Technologies. The Bookkeeper® process differs from earlier, less successful, attempts to neutralize acids in paper because it does not use any solvents or gasses that can damage inks, adhesives, paper or binding fabrics. The microscopic buffer materials (magnesium oxide) are dispersed and suspended in an inert liquid (a blend of non-toxic, fluorinated materials).
Books are mounted in treatment cylinders, where magnesium oxide is deposited to neutralize acids in the paper. Books are exposed to the treatment chemistry for about 30 minutes. The treatment solution is then drained from the cylinder, and a vacuum is applied for about 90 minutes to evaporate and condense the liquid carrier (perfluoroalkane) from the books (Harris 2000a:44; Library of Congress 2001). No harmful chemical residues remain in the paper and there is no need for after-treatment to remove odours or humidification to restore moisture to the paper. Until recently, the Bookkeeper® process has remained the only deacidification technology fully operational in the United States (Harris 2000a:40). While the Bookkeeper®
process is highly regarded in the USA, the Swiss regard the Battelle system which uses the non-aqueous solvent, magnesium titanium ethylate, dissolved in hexamethyl disiloxane as the best deacidification process (Herion 2000:48). According to Herion (2000:48), the Battelle system is suitable for both loose-leaf archive stock and bound library materials. Preservation Technologies has also developed new equipment that it is using to offer deacidification services for loose manuscript and archival materials (Library of Congress 2001).
Various deacidification technologies continue to be developed throughout the world.
Institutions are actively involved in developing programmes to create mass deacidification processes in other countries such as Germany, The Netherlands, Switzerland, France, the United Kingdom, Canada, Japan, South Korea, and China (Harris 2000a:46).
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Deacidification agents are as varied as the techniques. Through experimentation some deacidification agents like ammonia vapour (used extensively in India: Nehru Library) and morpholine vapour (developed by' the W. J. Barrow Laboratories) were proved to be ineffective in depositing an alkaline buffer that is capable of inhibiting acidic build-ups (Ritzenthaler 1993:144). Some agents that are being developed and tested like DEZ and submicron magnesium oxide hold great promise.
However, deacidification is not a panacea for all paper preservation problems. While it is the most important process in the preservation of paper it does not decrease the probability of biological attacks as some fungi thrive in alkaline conditions. It does not prevent oxidation decay or photochemical reaction. It does not strengthen paper already embrittled by acid hydrolysis (Gwinn 1987 :4; Jones 1999). Deacidification also raises the question of fastness of inks and pigments in the substances used as deacidification agents. Tests are necessary before deacidifying documents with inks and pigments.
In addition to deacidification, paper needs strengthening and support. Lamination, encapsulation and providing microenvironments are some of the ways used to stabilize and at times to support and strengthen paper. The following sections elaborate on these processes.
2.5.3.2 Lamination
William J. Barrow devised lamination in 1935 (McCrady 1993; Morrow & Dyal 1986:9; The National Archives of the Netherlands et af. 2001:63). It is a method of protecting and preserving embrittled or otherwise weak papers by placing them between sheets of thin, transparent thermoplastic material, which, when subjected to heat and pressure, with or without an adhesive, seals the paper in and protects it by making it more or less impervious to atmospheric conditions. It also increases its effective strength.
The paper is first deacidified and dried. It is then placed between two layers of cellulose acetate film approximately 0.001 inch thick. Layers of Japanese tissue or lens tissue are then placed over the film. The 'sandwich' is then subjected to intense heat (340-360 degrees Fahrenheit) and pressure (Morrow & Dyal 1986:9). Cold lamination can also be used instead of hot lamination (The National Archives of the Netherlands et af. 2001:63). The final product
is always a sheet slightly thicker and heavier than the original document and considerably stiffer and stronger. Lamination is an excellent method of improving the mechanical strength of documents, which are to receive considerable handling, but it also has both real and potential disadvantages. Unless the document is properly and adequately deacidified before it is laminated, it will continue to deteriorate despite the illusion of protection afforded by the laminating film.
In some archives and libraries lamination has been regarded as an appropriate method of last resort for much twentieth century material, since it can be carried out by semi-skilled, and therefore comparatively cheap labour; but it suffers from the inherent disadvantage of using heat or materials which have to be used with extreme care to avoid hazards to archival documents (Morrow & Dyal 1986:9). When lamination was first introduced, the tenn became almost synonymous with preservation ([he National Archives of the Netherlands el al.
2001 :63). However, it has been overtaken by encapSUlation. Lamination can no longer be considered a practical solution for preserving documents of enduring value (Rhys-Lewis
1999:164).
Unlike encapsulation, lamination is not instantly and completely reversible. The polyester film used in encapsulation is a stable, inert substance that is widely available (Morrow & Dyal 1986:9). Many institutions gave up lamination in favour of encapsulation in the early 1970s when the Library of Congress dropped it (McCrady 1992). Several delaminating projects have been undertaken worldwide to restore documents that were badly damaged by lamination in the 1960s and 1970s ([he National Archives of the Netherlands el al. 2001:63).
2.5.3.3 Encapsulation
Encapsulation has been defined as a form of protective enclosure for paper and other flat objects. It involves placing the item between two sheets (or one folded sheet) of clear plastic film (usually polyester) that are subsequently sealed along four edges. A sheet of buffered paper or board is sometimes included to increase support (Adcock. n. d). Encapsulation protects documents from physical wear and tear caused by frequent handling. Encapsulation is a technique of enclosing fragile, brittle, vulnerable, or damaged flat paper documents in a polyester film envelope (Morrow & Dyal 1986:9). It protects documents from air, dirt, and
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loss of text through breakage. Thus, the items can be safely handled by patrons without fear of damage. A conservator can also use encapsulation to store brittle or damaged papers before corrective treatment.
Encapsulation in Mylar was developed at the Library of Congress as an alternative to cellulose acetate lamination (McCrady 1993). It is a means of protecting fragile and damaged documents by sealing them between sheets of neutral polyester. Unlike lamination, polyester encapsulation is reversible and can be removed at any time with absolutely no risk to the document. Encapsulation can be instituted by sealing all the four edges of the polyester using an Ultrasonic Welder for polyester encapsulation or a double-sided tape recommended for archival purposes. Alternatively, polyester film enclosures of the U-seal (three-sided seal) or the L-seal (two-sided, one comer joined) type could be used.
Encapsulation does not stop a chemically unstable document from deteriorating. Thus, as it is the case with lamination, documents that are to be encapsulated should be deacidified first.
This makes encapsulation a less attractive option because deacidification is risky and expensive for non-conservators to do, and time-consuming for conservators (McCrady 1993).
Buffering an acidic document before permanent storage in an encapsulation is also recommended to slow down the future rate of deterioration. A buffered backing could be inserted in the enclosure if the document cannot be deacidified (McCrady 1984).
2.5.3.4 Microclimates
A microclimate has been characterised as any variation from the prevailing temperature and relative humidity of the surrounding environment (Wood Lee 1988). Microclimates or protective enclosures protect documents against rapid fluctuations in temperature and humidity, dust, light, atmospheric pollutants and mechanical damage (Mackenzie 1995:133;
Morrow & Dyal 1986:10; Shahani, Hengemihle & Weberg 1995:67; Weintraub & Wolf 1995:123). Specifically, a microclimate, or a microenvironment has been defined as an ,
"isolated environment within a small enclosed space such as an exhibit case, closed cabinet, drawer, box, or other container" (Weintraub & Wolf 1995:123).
Protective enclosures include folders, boxes, envelopes and polyester film. According to Mackenzie (1995:133) all records and archives other than bound volumes should be put into some form of secondary enclosure. Since protective enclosures do not stop ongoing deterioration, they have to be used for protecting treated documents (Gwinn 1987:28). If treatments for a particular document are in doubt protective enclosures are preferred to using a method that could further damage the document.
Protective enclosures are fundamental to protecting documents with intrinsic value.
Documents with intrinsic value dictate their retention in original format. Unlike other conservation treatments, protective enclosures do not obscure important features of a document. They can also be used when an archival institution does not have resources to restore damaged documents. According to McKern (1999) enclosures are used when items are not bindable; brittle but serviceable; and are in need of extra protection.
The best protection for documents is the closed box (Duchein 1977 :81; Peters 1996:9).
Recently, Passaglia (1987) studied microenvironments with specific reference to storage in the National Archives and Records Administration (NARA) and confirmed that closed boxes were valuable to the protection of materials. Passaglia (1987) presented models and calculations to estimate the effectiveness of various containers for protection of archival materials from environmental pollutants.
2.5.3.5 Conservation and restoration facilities
The implementation of the conservation-restoration processes described above largely depends on the existence of suitable facilities. According to Duchein (1977:54) setting up a modem archive repository without some conservation workshops is inconceivable. A viable conservation and restoration programme should be supported by facilities such as a bindery, a restoration workshop, reprographic laboratory, equipment and materials (Duchein 1977:54;
Khayundi 1995:33; Mbaye 1995:43). Most archival institutions surveyed by Mbaye (1995) did not have technical workshops to carry out conservation and restoration activities. In some SSA countries conservation workshops exist, but most of the equipment has broken down due to
lack of maintenance and the difficulty of getting spare parts due to foreign currency constraints (ESARBICA 2002; Khayundi 1995:33; Mbaye 1995:43).
No amount of training or policy making in the field of preservation can facilitate conservation treatment in the absence of basic preservation facilities like workshops. For instance, in 1978 Mr Ranbir Kishore, an expert in conservation from India, could not demonstrate most conservation techniques when he was brought to Kenya to assist in conservation training because there were no basic conservation and restoration facilities in the country (Matwale
1995:49).
2.5.4 Inks and the preservation of paper-based records
It is often the combination of ink and paper that determines the life span of the information contained in records and archives. In creating records of enduring value the ink should be carefully selected as it influences the preservation of information. According to Ritzenthaler (1993:32) archivists should be aware of the common inks as well as their characteristics.
Although, there has been limited research on the effect of ink on archival materials, it is apparent that inks have a potential to tilde due to prolonged exposure to light (Ritzenthaler 1993 :32; Thomas 1990a). They can also bleed or transfer if exposed to moisture. They can also weaken the paper.
For instance, the W. 1. Barrow Research Laboratory (1967) found that the printed areas of 19th century book pages were weaker than the unprinted areas. The chemists at the W. J.
Barrow Research Laboratory summed up their findings as follows:
While writing ink used in the nineteenth century is known to be injurious to paper because of its sulfuric acid content, conclusions from this study indicate that printer's ink did no visible damage to the nineteenth century papers tested. There was, however, a loss of 30% in folding strength due to encrustation of the ink and some loss in 13%
of the papers due to injurious ingredients (other than carbon and oil) in the ink (W. J.
Barrow Research Laboratory 1967:37).
Over centuries, people have used a variety of ink types such as carbon, iron gallotannate, copying, modem manuscript, printing, typewriter ribbon, non-impact printing and ballpoint
pen inks to records their activities and thoughts. Nowadays, most documents are created using typewriter ribbon, non-impact printing and ballpoint pen inks. Archivists should be concerned with research into the stability and permanence of these inks so that they can recommend the right ink to record creators (I'homas 1990a).
There must be thousands of printing inks sold today, and ink manufacturers can be expected to change the formula whenever they believe this would improve the product. So it would be risky to generalize about the stability and permanence of inks now on the market, except to say that there have been no reports of really destructive printing inks lately. Experience has shown that printing ink is normally long lasting and that the major threat to documentary materials is the quality of the paper and not the quality of the ink. On the other hand, standards for inks for duplicators are not archival and the process does not appear to be capable of creating permanent records.