Activities associated with maintaining library, archival or museum materials for use, either in original physical form or in some other format. Preservation is a broader term than conservation: conservation activities form part of a total preservation program. Preservation includes both activities taken to repair or treat damaged materials (retrospective) and activities taken to prevent or delay material becoming damaged (preventive preservation).
National Library of Australia. Library Prevention Glossary
The use of procedures to preserve and repair the physical structure of an item. All processes ideally should be reversible.
National Library of Australia. Library Prevention Glossary
Causes of deterioration include
- Changes in papermaking and binding practices
- Acidity
- Environment
- Insect pests
- Rodents
- Fungus
- Use and abuse by people
Parchment: The split skin of an animal, usually a sheep, goat, or young calf, bleached, stretched, scraped, and prepared for use in bookbinding or as a writing or painting surface, from about the 2nd century A.D. until well after the invention of movable type.
Vellum: A thin, fine parchment made from the skin of a newly born lamb, kid, or calf, dressed and polished with alum for use as a writing surface and in bookbinding, before paper came into use in the 15th century.
Reitz. ODLIS.
Paper- Early papers made from cotton and linen rags
- 1830’s introduction of alum-rosin sizing replacing gelatin and gelatin-alum sizing
- Breaks down over time to produce sulfuric acid which eventually causes paper to deteriorate and become brittle
Chemicals added to paper and board during manufacture to make it less absorbent, so that inks will not bleed, and the image will have better definition. Sizing can also be used to strengthen weak papers. Rosins, gelatin, starches and synthetic resins are used as sizing agents.
National Library of Australia. Library Prevention Glossary
Chemicals added to paper and board during manufacture to make it less absorbent, so that inks will not bleed, and the image will have better definition. Sizing can also be used to strengthen weak papers. Rosins, gelatin, starches and synthetic resins are used as sizing agents.
National Library of Australia. Library Prevention Glossary
- 1850 replacement of rag pulp paper with wood pulp paper
- <cellulose fibres of wood 10 times smaller and much more fragile than those of textiles
Acid paper
Paper which has a pH value lower than seven. An important factor in the preservation of printed materials, acidity causes paper to yellow and become brittle over time. To solve this problem, publishers are encouraged to use acid-free or permanent paper in printing trade books.
Reitz. ODLIS
AcidityPaper can develop an acidic nature because of:
- alum-rosin sizing used in papermaking
- atmospheric conditions (e.g. pollution such as sulfur dioxide)
- storage next to other acidic materials (e.g. cardboard, wood)
- See: Librarians and Paper Permanence http://cool.conservation-us.org/byorg/_abbey/ap/ap06/ap06-6/ap06-605.html
- Protective enclosures
- Deacidification
- Reprographic services
- Digitization
- Alkaline paper
- Shelving
An example of a protective enclosure includes a phase box.
Double-tray box also known as a drop-spine or clamshell box.
Acid-free folders.
Encapsulation
Deacidification:
A common term for a chemical treatment that neutralises acid in a material such as paper, and that may deposit an alkaline buffer to counteract future acid attack. While deacidification may increase the chemical stability of paper, it does not restore strength or flexibility to brittle materials.
National Library of Australia. Library Prevention Glossary
Mass deacidification
- No "ideal" mass deacidification process
- Current systems and their users include:
| Battelle | Swiss National Archives National Library Leipzig Eschborn, Germany |
| Bookkeeper | Library of Congress |
| Libertec | Berlin & Munich State Libraries, Germany |
| Neschen | State Archive of Lower Saxony, Germany National Archive, Berlin, Germany |
| Wei T'o | National Library of Canada |
Reprographic services
Electronic digitization
Electronic digitization refers to the capture of the document in electronic form through a process of scanning and digitization. The scanned image can be made over the Internet, or stored electronically, usually on magnetic or optical storage media.
Wooden vs. metal shelves
From the perspective of preservation, it is best to store collections on metal shelving, since wood shelving can give off damaging pollutants. If wood shelving must be used, shelves should be sealed with polyurethane. Oil-based paints and stains should be avoided. In addition, shelves can be lined with museum board, polyester film, glass, Plexiglas, or an inert metallic laminate material to prevent materials from coming into direct contact with the wood.
Metal shelves should be powder coated electrostatically as other finishing processes may continue to give off fumes.
Environmental factors
Air quality
Light
Basic Conservation of Archival Materials http://www.cdncouncilarchives.ca/public_free.html
A Manual for Small Archives: Conservation and Security https://web.archive.org/web/20040310154328/http://aabc.bc.ca/aabc/msa/6_conservation_and_security.htm
European Commission on Preservation and Access. A Virtual Exhibition of the Ravages of Dust, Water, Moulds, Fungi, Bookworms and Other Pests. http://web.archive.org/web/20050306230604/http://www.knaw.nl/ecpa/expo.htm
NARA: Preservation http://www.archives.gov/preservation/
National Library of Australia. Library Preservation Glossary. http://www.nla.gov.au/chg/useful-resources/library-preservation-glossary
Reitz, Joan M. ODLIS http://www.abc-clio.com/ODLIS/odlis_A.aspx
Unesco. Safeguarding Our Documentary Heritage. http://webworld.unesco.org/safeguarding/en/
University of Illinois at Urbana-Champaign. Proper Care and Handling of Books and Paper Materials. http://www.library.illinois.edu/prescons/
- Microfilming
- Photocopying
- least expensive
- Photography
Electronic digitization
Electronic digitization refers to the capture of the document in electronic form through a process of scanning and digitization. The scanned image can be made over the Internet, or stored electronically, usually on magnetic or optical storage media.
Wooden vs. metal shelves
From the perspective of preservation, it is best to store collections on metal shelving, since wood shelving can give off damaging pollutants. If wood shelving must be used, shelves should be sealed with polyurethane. Oil-based paints and stains should be avoided. In addition, shelves can be lined with museum board, polyester film, glass, Plexiglas, or an inert metallic laminate material to prevent materials from coming into direct contact with the wood.
Metal shelves should be powder coated electrostatically as other finishing processes may continue to give off fumes.
Environmental factors
- Different records/media have different optimal environmental conditions
- Paper usually forms the bulk of a collection of mixed archival materials so…
- Guidelines for paper set the preservation norm
- Air quality
- Dust
- Light (ultraviolet most damaging)
- Temperature
- Humidity
Air quality
- Primary sources of gaseous pollutants identified in deterioration of archival collections
- Sulfur dioxide, nitrogen dioxide, ozone
- Particular pollutants include grit, smoke, dust, etc.
- Keep doors and windows closed
- Use materials known to be benign to collections
- Check and replace air filters/scrubbers regularly
- Locate air intakes in as “clean” a location as possible
Light
- All light damages archival material by fading, yellowing and structurally weakening them
- UV light is more damaging, shorter wavelengths cause greatest amount of photochemical deterioration
- Sunlight and fluorescent lights the two main UV light sources
- UV filters e.g. acrylic sheets, film, foils, coatings
- Storage area
- Keep materials covered or boxed when not in use
- Use blinds to eliminate sunlight
- Apply UV filter film to windows
- Select fluorescent tubes with low or no UV emissions or use UV filters on tubes
- Turn lights off when area not in use
- Storage area
- Keep materials covered or boxed when not in use
- Use blinds to eliminate sunlight
- Apply UV filter film to windows
- Select fluorescent tubes with low or no UV emissions or use UV filters on tubes
- Turn lights off when area not in use
- Exhibit area
- Monitor area with lux and UV meters
- Use copies whenever possible
- Never have archival items on permanent display
- Use a dimmer switch, lower watt bulbs or move light source further away
- To reduce heat light source should not be inside or close to exhibition case
- Of primary importance in preservation of archival materials is providing a cool and dry storage area
- In general, with every 5C increase in temperature, reaction rates double, e.g. archival records stored at 20C will have half the life expectancy of those stored at 15C
- General rule of relative humidity:
- When relative humidity is halved the life expectancy of the record is doubled
- High relative humidity levels can lead to growth of mould and mildew, increased chemical deterioration, cockling of paper/parchment, warping of books, increase in likelihood of pest infestations
- Low relative humidity leads to drying out of archival records making them brittle and susceptible to cracking
- 1999 ASHRAE Handbook re-evaluated environmental standards for museums, libraries, and archives
- A good compromise for a mixed collection 45% +/- 10% relative humidity and 18°C to 20°C
- Insect pests
- Rodents
- Fungus
- People
- Shelving practices
Basic Conservation of Archival Materials http://www.cdncouncilarchives.ca/public_free.html
A Manual for Small Archives: Conservation and Security https://web.archive.org/web/20040310154328/http://aabc.bc.ca/aabc/msa/6_conservation_and_security.htm
European Commission on Preservation and Access. A Virtual Exhibition of the Ravages of Dust, Water, Moulds, Fungi, Bookworms and Other Pests. http://web.archive.org/web/20050306230604/http://www.knaw.nl/ecpa/expo.htm
NARA: Preservation http://www.archives.gov/preservation/
National Library of Australia. Library Preservation Glossary. http://www.nla.gov.au/chg/useful-resources/library-preservation-glossary
Reitz, Joan M. ODLIS http://www.abc-clio.com/ODLIS/odlis_A.aspx
Unesco. Safeguarding Our Documentary Heritage. http://webworld.unesco.org/safeguarding/en/
University of Illinois at Urbana-Champaign. Proper Care and Handling of Books and Paper Materials. http://www.library.illinois.edu/prescons/
