Document Conservation and Preservation

Some Basic IssuesAnd Methods

Causes of Deterioration• Temperature and

Relative Humidity.• Atmospheric

Pollutants.• Light.• Biological Agents.• Abuse and

Mismanagement.• Disasters.

Paper and Acid

• Acidity accounts for 90 percent of paper destruction.

• Paper production.• Reasons for acidity.• Definition of acid and

acid-free.

Relative Humidity• Amount of water vapor actually

held in a specific amount of air

• low relative humidity may lead to desiccation and embrittlement of some materials

• Fluctuations can cause cockling in paper, flaking ink, warped covers on books, cracked emulsion on photographs, and cause mold growth.

• Steady RH between 45% and 60% should be the goal

• no more that 5% shift in 24 hours period

Air Quality

• Are external pollutants filtered out?

• Materials the displays are made from may outgas

• Other exhibition materials may outgas

• Gases form acids that attack exhibition materials and effect each media differently

Silver Mirroring

Images courtesy of: http://iaq.dk/image.htm,

http://iaq.dk/silvermirror/Gallery/Allsurface2.html

Temperature• Temperature effects

relative humidity

• Heat accelerates deterioration: the rate of most chemical reactions, is approximately doubled with each increase in temperature of 10°C

• Should remain fairly stable at or around 18-21C

• no more than 5 degree shift per month

• Lighting may raise temperature

Photographic Security and Proper Storage

• Metal Containers.• Temperature Constant:

Prints, 65 degrees. Negatives, 45 degrees.

• Humidity Constant: 45 percent.

• Gloves and Use conditions.

• Separate Negatives from Prints.

Mold Damage

Cockling

Shrinking and Flaking Emulsion

Low Cost Solutions• Implement an

environmental monitoring program

• Avoid basements and attics

• Add weather stripping around doors and windows

• Install an air conditioning unit

• Ensure proper drainage around buildings

• Install storm windows to moderate temps and reduce condensation

• Use humidifiers and dehumifiers

Conservation Videos

http://www.youtube.com/watch?v=nmC10gCi-g0

http://www.youtube.com/watch?v=JXrs8L-LUd8&NR=1

National Archives

Flattening Maps and Plans

Photographic Preservation

http://www.youtube.com/watch?v=geqVsJJK5rs

http://www.youtube.com/watch?v=fcDlbNi-9D0&feature=related

The Archives Reading Room