Professional Development

Paper:

The natural aging process of paper will cause it to become weak and brittle. Ensure that paper items are handled carefully and are protected when storage or in use. Be sure to provide support oversized items when moving them, large pieces of coroplast are useful for this task.

When considering how to deal with paper items, consider the type of medium used, e.g., graphite, ink, charcoal, water-colour etc.

DO NOT encapsulate graphite or charcoal items as the static of the polyester will ruinaffect the item.

Acidic paper will contaminate de-acidified or non-acidic paper items; if these items must be stored together, place in enclosures to protect the items from acid migration. Use acid free paper to "buffer" to two items.

Books:

Books are designed to stand on a shelf with the support of other books of equal height and depth. They should be placed close enough to support each other but loose enough to be removed from the shelf. Oversize books may be laid flat; damaged or rare books should be placed in a box or wrapped in acid-free wrapping/tissue paper. Use a book cradle for displaying volumes,

Parchment and Vellum:

Both parchment and vellum are made from de-haired, limed pelts which are dried at ordinary temperatures under tension. High humidity will cause the sheet to swell; low humidity will cause it to shrink and stiffen. Store flat if possible, however, folded or rolled parchment is best left as is.

Photographs:

Most photographic prints have two parts, an image layer and a support layer. The image layer differs in composition but can be divided into two categories: black-and-white and colour. Light damages all photographic prints but most unstable are the dyes used in colour photographs. Never touch the front of a print as skin oils can damage the image layer.

Photographic Negatives and Slides:

Negatives are composed of an image layer and a support layer and also react in a similar manner to exposure to light as a photographic print. The support layer is usually composed of a polyester, cellulose acetate or a cellulose nitrate film. Slides also have a support layer of film but the image layer is a positive image and, like colour prints, is formed from unstable dyes. Cellulose nitrate film gives off acidic fumes which contaminate other materials.

Nitrate film is also highly flammable and has been known to self-ignite under conditions of high temperature.

Magnetic Media:

This includes a variety of carriers for recorded information such as video and audio cassettes, 8 track and reel to reel audio tapes and computer tapes, disks and diskettes. The surface of the tapes contains magnetic particles that store information which can be read by playback equipment. The surface layer is particularly susceptible to damage from skin oils.

Because these magnetic particles can be erased by a close proximity to a magnetic field. Keep away from magnetized objects as well as electrical equipment, fixtures and motors, transformers and high voltage lines.

The deterioration of archival materials is no more or less than an indication of the forces of nature doing their job. It is important to understand enough about the physical characteristics of materials in the collections to figure out what nature is up to and to try and delay the inevitable deterioration.
 

Light

Light is measured in units of intensity called a lux. High intensity light can induce chemical reactions which cause deterioration of archival items such as fading of dyes and pigments, discolouring supports and structurally weakening them. Sunlight and fluorescent light are sources of ultraviolet light which is potentially capable of damage to collections.

Light also generates heat which in turn accelerates the rate at which materials age.

Light levels should be kept as low as possible and the length of exposure should be limited. The easiest way to do this is to ensure that the collection is covered or boxed. Avoid high intensities of any kind of light and reduce the levels of daylight using curtains and blinds. Fluorescent lights can be covered in filtering plastic sleeves to reduce UV levels. Turn out the lights when the collection is not in use.

Relative Humidity

Relative humidity (RH) is the term used to describe the amount of water vapour in the air at a specific temperature. It is expressed as a percentage of the total water vapour that the same air will hold at the same temperature. A high RH will encourage mould growth and foster destructive chemical reactions. High humidity also will cause structural deformation of paper and books.

A low RH will cause archival materials to become brittle and make them susceptible to cracking especially when handled. Small changes in RH will cause archival materials to expand and contract, which weakens physical bonds and can shorten the longevity of materials.

Relative humidity should be allowed to change gradually from one season to the other but should be kept between 45% and 55%. Avoid daily fluctuations or keep them as small as possible no more than + 3%. The use of air conditioners, humidifiers and dehumidifiers can even out RH levels in contained areas. Inexpensive hygrometers can be purchased to monitor relative humidity.

Temperature

        Changes in temperature will alter relative humidity correspondingly. Higher temperatures accelerate chemical reactions and cause materials to deteriorate at a faster rate. Low temperatures can cause condensation on the surface of materials. Rapid temperature changes cause internal stresses on materials.

       Remember:

• Maintain a constant temperature day and night
• Do not turn the heat off on weekends and holidays
• Rapid fluctuations are very harmful
• A lower temperature (18-20 C) is recommended for archival collections
• Temperatures above 25 C are not acceptable for archival material.

Pollution

Gaseous and particulate contaminate can cause a great deal of damage to archival material. If the archives are located in an urban or industrial area, industrial gases and automobile exhaust should be a concern. Indoor pollutants are also harmful. Cleaning supplies, paints, untreated wood, adhesives, plastics, and paper products with a high lignin content all contain harmful gases. Particulate like grit, grime, smoke and dust are abrasive and acidic.

        Indoor gaseous pollutants can be controlled by ensuring that all cleaning and paint supplies are stored well away from the collection. All wood should be sealed and any fresh paint should be cured before being placed in the area. Do not allow smoking or cooking near the collection and clean and dust the area regularly.

Pests and Mould

        Archival collections are very attractive to insects and rodents and can provide the nutrients needed for mould to grow. Their presence in the collections is determined by environmental factors (high temperature and relative humidity) as well as the cleanliness and maintenance of the area.

        Check collections on a routine basis. Isolate any new material that comes into the collection and inspect it thoroughly before placing it with the rest of the collection. Control the relative humidity (mould will form at 65% RH) and lower the temperature as much as possible. Do not permit eating or drinking in the area.

Disasters

Identify all possible causes of disasters and plan what to do in an emergency. 

Fire: Will damage the collection through heat, smoke and water as well as by burning the records. Make sure the archives has some form of fire detection and fire suppression equipment.

Floods or leaks: Will encourage the growth of mould (within 24 hours) and cause irreversible damage to archival material. Do not store archival materials under water pipes. Have the roof, eaves troughs, down spouts and drainage systems inspected and maintained regularly.

Theft and vandalism: I'll just leave this one to your imagination. Create an atmosphere that discourages theft and vandalism. Also keep in mind that the majority of insurance claims for fine art collections are the result of the objects having been dropped.
 

III. Protect the Collection

Storage

Place all archival material in some form of protective enclosure. House the material in an appropriate sized box and place it loosely enough that it can be removed easily but will not sag. Provide adequate shelf space for the collection. Remove or segregate acidic enclosures to prevent them from damaging other material.
The shelving area should have space for over sized or odd sized items. Metal shelves are preferable but wooden shelves are acceptable if coated with acrylic latex paint. The shelves should be secure and solidly braced. No items should be stored on the floor.

Protective Enclosures

Papers and boards used for enclosures must be acid-free. Buffered products may be used for all archival materials except photographs. Plastics may be used if they are inert or chemically stable. Polyester, polypropylene, polyethylene and tri-acetate are acceptable. If you are in doubt about the components of a plastic, do n€™ot use it. All enclosures must permit the removal of the contents without risk of damage.

Handling

• Always have clean hands and do not use hand lotions before handling materials.
• Make a habit of wearing lint-free cotton gloves.
• Use both hands or support an item with a stiff paper when moving or carrying it.
• Use a trolley or have another person help to carry oversize or heavy objects.
• Never use pens near archival material.
• Always remove an object from a protective enclosure by pulling on the enclosure, not the object.

Finally, encourage the staff, volunteers and visitors to "Think Preservation".

[The 1997-1998 ACS project was made possible by financial assistance from the federal government through the Canadian Council of Archives, and provincially through SCC, Heritage Branch, the Saskatchewan Archive Board, the University of Saskatchewan Archives, the University of Regina Archives, the St. Thomas More College Archives, Oblates of Mary Immaculate Archives, Roman Catholic Diocese of Saskatoon Archives, and the Diefenbaker Canada Centre.]