Posted with permission of Jefferson County Public Library thanks to Kay Pride.

Map & Book Preservation





This brochure has been prepared in response to requests received each year from individuals with small collections of books, photographs and/or family documents they wish to preserve.

Every part of a book, document, or work of art (which may include paper, cloth, leather, photographic emulsions, inks, pigments, plastics, adhesives, etc.) reacts to its environment and will deteriorate with age. This process can be slowed by keeping your collection in a stable environment.

The environment is made up of four components: heat, relative humidity, light, and pollutants. The ideal environment is cool, clean, dry, and dimly lit. Hi heat, especially with high relative humidity, rapidly accelerated deterioration.

If a document is too fragile to handle, a photocopy on archival paper is an excellent way to retain the content of the piece. Use the copy and tuck the original away for safe keeping.




Avoid storing any collection in an area that stays very warm or experiences extreme temperature fluctuations, such as your attic or garage. As a rule, 65-70 F is best for collections.


Relative Humidity

Library materials respond to fluctuations in relative humidy (RH) by losing and gaining moisture. It is more important to maintain a stable environment than to maintain a specific RH. Evidence of fluctuating RH damage is cockled paper, flaking or cracked photograph emulsions, warped book covers, warped and/or cracked vellum and parchment documents and books.

RH is related to temperature. Uncer normal conditions, if your room temperature is stable, the RH probably is too.

In Colorado and other arid regions the RH is naturally low. This causes some items to become brittle. There are advantages to low (30%) RH:

  • Slower absoprtion of pollutants
  • Less damage due to light exposure
  • Less change in moisture content
  • Greater stability




A water disaster requires an immediate response. Wet books and paper will begin to grow mold in less than 48 hours, and mold spreads fast.

Remove and stabilize all wet materials.

  • Freeze them immediately
  • If the emergency is small, wet books can be stood up on end and air dried in an open, well-ventilated space.
  • Controlled exposure to sunlight will kill mold spores. Segregate moldy or wet books from the rest of your collection until you are sure they are clean and dry.

Dry and stabilize the environment.

  • Use fans to move the air.
  • Use a wet-dry vacuum.
  • Check all carpeting/flooring under heavy furniture (like bookshelves).



Exposure to light accelerates the deterioration of all organic materials. An object exposed to low light for a long period of time will deteriorate just as much as an object exposed to strong light for a shorter period. Ultraviolet (UV) light is the most damaging; both sunlight and fluorescent light are high in UV.

In Colorado, with its great weather and high altitude, extremely high UV levels are a fact of life and a constant danger to collections as well as to people. The less direct light, the better.

  • Don't display works of art on walls that are opposite windows.
  • Place bookshelves on walls that are not exposed to direct sun.
  • Place valuable or fragile items in an archival enclosure to protect them from an light exposure. If exposure to light cannot be minimized, UV filters are available for specific applications.



In the home library, particulates (dust, crumbs, etc.) are a problem. Particulates are abrasive and attract pests such as insects and mice.

Clean dusty books before opening to prevent dust from falling inside. To dust a book:

  • Hold the book tightly closed while removing it from the shelf.
  • Use a cloth treated to pick up dust (One-Wipes are good); draw the cloth across the head of the book from the spine to the outside edge.
  • Dust the rest of the outside of the book. Do not rub or scrub with the cloth.

Shelve books with the spine out. The books should support each other, but should not be packed tightly.

Line book shelves with polyester (an inert, transparent plastic) to preclude any problems caused by wooden or painted shelving.

Store oversize books or documents flat.

Support the hinges of books on display to prevent strain (and possible breakage). Never display a book open to the same spot for an extended length of time.


Handling & Repair of Valuable Materials

Place fragile or valuable items in a protective enclosure to minimize exposure to light, dust, pollutants, and handling, then leave along. Restrain any impulse to "fix it up" which will devalue the piece.

  • Don't use pressure sensitive tapes (Scotch tape for example). These stain and embrittle paper and are very difficult to remove. Instead, wrap and store a damaged item in an acid-free enclosure until it can be professionally treated.
  • Don't laminate (sealing items in plastic with heat). This process cannot be reversed. Encapsulation (placing an item between sheets of polyester film), is a good archival alternative. Polyester sleeves can be purchased pre-sealed on two or three sides.
  • Don't tough the emulsion surface of photographs.

Hire and expert to undertake conservation procedures such as washing, deacidifying, and repair of paper, rebinding, fumigation or photo restoration.



ABC for Book Collectors. John Carter, 1995.
Glossary of book terminology

Archives and Manuscripts: Conservation. Mary Lynn Ritzenthaler, 1984.
A classic in the library preservation field.

The Bloomsbury Review Booklover's Guide. Patricia Jean Wagner, 1996.
General information for the home library.

Care and Identification of 19th-century Photographic Prints. James M. Reilly, 1988.

Caring for Your Family Treasures: Heritage Preservation. Richard W. Long, 2000.
Practical guide to caring for objects of value.

Cleaning and Preserving Bindings and Related Materials. Carolyn Horton, 1969.
Common-sense procedures for library collections.

The Permanence and Care of Color Photographs. Henry Wilhelm, 1993.





Into the future: on the preservation of knowledge in the electronic age. Terry Sanders, 1997.
Problems faced when preserving digital media.

Slow Fires: On the Preservation of the Human Record. American Film Foundation, 1987.
Excellent introduction to the problem of brittle books aimed at the general public.


Preservation Websites

American Institute for Conservation of Historic & Artistic Works (AIC)
see links: Caring for Your Treasures; Selecting a Conservator

Colorado Preservation Alliance
state and local resources; links to national sites

Conservation Online (CoOL)
complete resource


information sheets on a myriad of museum topics

NorthEast Document Conservation Center
complete resource


The Old Map Gallery
1746 Blake Street | Denver, Colorado 80202