Preservation Frequently Asked Questions
- How should I store my books?
- How should I display documents or works of art on paper?
- Can I save wet books? What if my books are moldy?
- How can I get rid of the smell of mildew in my books?
- How can I preserve my family photographs for my grandchildren?
- I have an infestation. How can I get rid of bugs in my books?
- How can I preserve my newspaper clippings?
- The leather on my books is worn and scuffed. Should I oil my leather bindings?
- Will the Library of Congress restore or appraise my books?
- Will the Library of Congress deacidify my book collections?
- What If I have other questions about preservation of library and archives materials?
-
Store books out of direct sunlight and where air can circulate freely. Store them away from windows and don't put them on shelves against outside walls.
Store books on flat, smooth shelves that are strong enough to support their weight. Ideally, books should not be in contact with unsealed wood because it can release damaging acidic vapors. Line shelves with acid free board to prevent this problem. Stand books vertically side by side. Keep similar sizes together: small books next to small books, and large books next to large books. Use bookends to keep the books from falling over, and be sure they are high enough to support the books completely.
Avoid storing books in an attic or basement because attics get too hot and basements get too damp. Both are also subject to rapid changes in temperature and humidity levels. Keep books out from under plumbing and water pipes; water damage from these sources is all too common.
To protect books with monetary or sentimental value, keep them in custom-fitted archival boxes made from high-quality materials.
How should I display documents or works of art on paper?
Protect such items by hinging them into mats that have both a back board and a window board. Ask your picture framer for museum-quality mat board. To be of museum quality, the board must be free of acid (alkaline, ideally pH 7 to pH 9) and colored with non-damaging dyes that don't run if they get wet. The board could be 100% cotton rag or chemically purified wood pulp (high alpha-cellulose and negative to lignin). Poor quality mats can damage the pictures they are supposed to protect. The most common damage is dark yellow staining, particularly around the edges of the window mat that frames the picture. Known as "matburn," the stain is caused by migration of acidic components in the board. Matburn can discolor an item dramatically and is also an indication of chemical damage to the paper.
The method used to mount the document or picture in the mat is critical. It should be attached to the backboard of the mat with long-fibered paper hinges (Japanese paper, usually) and cooked starch paste. Although a straightforward procedure, accomplishing it successfully can be tricky, so it's best to leave the task to a trained conservator or professional picture framer. A less complicated, but still archivally sound, alternative is secure the item in the mat with photocorners. High-quality polyester or paper photocorners can be purchased from conservation suppliers.
NEVER hinge pictures with pressure-sensitive tape (including masking tape, "invisible" tape, quick-release tape, cellophane tape, double-stick tape, and the so-called "archival" tapes). NEVER use rubber cement, stick glue, spray adhesives, or dry-mount adhesives. Do not use brown paper tape (moisture-activated gummed adhesive) or animal glues. All tapes and adhesives of these types will stain the paper and and may cause inks and colors to "bleed." Many lose their adhesive properties and fall off with age, leaving behind a residue that is unsightly, damaging to the item, and difficult (or impossible) to remove. If removal of such adhesives and the stains they cause is possible, the work should only be entrusted to a trained conservator. Improper treatment can damage items irrevocably, greatly reducing their beauty and value.
Use a good frame that is well-constructed and has mitred joints. The frame should be sturdy enough to support the weight of the object. Glass or acrylic should be used as glazing. Glazing should never touch the work of art. The preservation purpose of a window mat or spacer is to prevent such contact.
All light, natural and artificial, damages paper-based materials. Sunlight and fluorescent lights are particularly damaging. Light damage can be reduced by using ultraviolet-filtering glazing. Acrylic glazing should not be used in the framing of pastels, charcoal drawings, or pictures with flaking pigments because they tend to develop a static charge that can lift powdery media right off the paper.
If the document or art work to be framed needs conservation treatment, a conservator should be consulted before any work is undertaken. This is particularly the case with items that have high monetary, historic, or sentimental value. A referral service that can help you find an appropriate conservator or conservation treatment center is maintained by The Foundation of the American Institute for Conservation (FAIC):
The Foundation of the American Institute for Conservation (FAIC)
1156 15th Street, NW, Suite 320
Washington, DC 20005-1714
202-452-9545
202-452-9328 (fax)
info@aic-faic.orgCan I save wet books? What if my books are moldy?
Yes. Books can be air-dried, or frozen and then dried at a later date.
The most important thing to do to save your wet books is to take action immediately, or as soon as possible, after they have gotten wet. In warm and humid conditions, mold can begin to grow within 24-48 hours after the materials have gotten wet. Stabilize and air dry as much of the collection as possible. What cannot be air-dried in 48 hours, can probably be frozen to stabilize and dry at a later time. Check with a conservator.
Fan volumes open and stand them on the top or bottom edge on an absorbent material which is changed as it becomes wet. As the book dries turn it upside-down. Humidity levels should be maintained below 75% RH with dehumidifiers. Low temperatures will assist in avoiding mold.
Increasing air circulation will dry out most items efficiently. Use electric fans to provide maximum air circulation, but do not point them directly at the drying books. Weather permitting, set up a drying space outdoors, under cover.
Mold is the greatest risk and hazard, both to books and to humans. If you suspect or see mold, or think that the water may have been contaminated with sewage or harmful chemicals, you must wear protective clothing, gloves, and a mask while salvaging your books. Also, take strict precautions to protect your skin and lungs. If mold is present, seek professional advice and proceed with caution. If any negative health effects are observed, contact a doctor, mycologist, or both, before proceeding. Local colleges and universities can help you find a mycologist.
How can I get rid of the smell of mildew in my books?
The smell comes from biological growth on books that are stored in damp, dark, cool locations. Check for active or dormant mold. Remove the materials to a drier (but still cool) environment, and make sure that plenty of air is circulating around them. These conditions should render the biological growth dormant. If the mildewed materials are stored for an extended period under such conditions, the smell will eventually disappear of its own accord. The same technique can be applied to dry books affected with active mold. If you can see mold growth, DO NOT attempt to clean it off until the materials are thoroughly dry. Premature cleaning attempts will grind the mold into the covers or paper and cause stains that are often impossible to remove.
A short exposure to sunlight and circulating air outdoors also may help to rid the books of the mildew smell. Remember, though, that light damages paper-based materials. Drying materials in the sunlight may result in some darkening or fading of book materials and paper, so select this approach only with materials for which such damage is considered acceptable.
How can I preserve my family photographs for my grandchildren?
Store photographs at 68 degrees F. and 30-40% relative humidity (HR) in a closet or air-conditioned room. Don't store them in the attic or basement. Higher humidity levels speed up deterioration; very low humidity may cause prints to crack, peel or curl. Storage at lower temperatures is particularly advised for contemporary color prints.
Avoid exposing photographic materials to anything containing sulfur dioxide, fresh paint fumes, plywood, cardboard, and fumes from cleaning supplies. Store photographs in proper enclosures made of plastic or paper materials which are free of sulfur, acids, and peroxides. Preservation quality paper storage enclosures are available in buffered (pH 7.5-9.5) and unbuffered stock. Stable plastic enclosures are made of uncoated polyester film (Dupont Mylar Type D or ICI Melinex 516), uncoated cellulose triacetate, polyethylene, and polypropylene. All materials used for storing photographic collections should pass the PAT (Photographic Activity Test) and will be marked as such by suppliers of high quality photographic enclosures. If relative humidity cannot be controlled consistently below 80%, plastic enclosures should not be used because photographs may stick to the slick surface of plastic.
Avoid acidic paper envelopes and sleeves, polyvinyl chloride (PVC) plastic, rubber bands, paper clips, and poor-quality adhesives such as pressure-sensitive tapes and rubber cement. Buffered enclosures are preferred for deteriorated photographic prints on poor-quality mounts.
Avoid the cheap, readily available "drugstore type" photo albums. Instead buy albums made of high-quality materials. Generally, use photo corners and only those materials that are known to have passed the PAT tests. Particularly, avoid albums with sticky adhesive pages.
I have an infestation. How can I get rid of bugs in my books?
Identify the bug if possible (trap one with sticky pest strips) and try to answer the following questions that a professional will ask you:
Is the insect already dead or alive and how many insects are there?
How many books are affected and with what kind of damage?
Have you seen insects like these elsewhere in your home?
Where have the books been stored and are they damp or moldy?
How valuable and old are the books?
Isolate the affected books by placing them in a tightly sealed plastic bag. Seek assistance from an entomologist. A local university or state extension service should be able to put you in touch with one. Fumigation must be performed by professionals under controlled conditions. Non-chemical preventive measures against insects include:
Seal entry points including windows, doors and put filters on vents.
Keep room temperatures and humidity levels low (insects need water, too).
Keep the environment clean and dusted, and don't store books near food or rubbish, etc.
Dessicant dusts like diatomaceous earth or silica, can be used around the perimeters of a room, but will not be effective for insects with a winged portion of the life cycle.
How can I preserve my newspaper clippings?
Newspaper is made from wood fibers and it will turn dark and brittle very quickly, particularly when exposed to light. Although it can be chemically treated to slow down further deterioration, many of the treatments will also darken the paper. Newspaper will damage other paper or photographic materials with which they are stored if the other items are not protected from them.
The only way to preserve the original is to store them properly:
Place clipping in a polyester film folder with a sheet of alkaline buffered paper behind it.
Put the polyester folders in file folders and boxes of high-quality acid-free, alkaline buffered materials.
Store in a cool and dry location, such as a closet in an air-conditioned room.
The leather on my books is worn and scuffed. Should I oil my leather books?
Leather dressings were at one time thought to be useful in extending the life of leather bindings. Experience has shown, however, that the benefit is primarily cosmetic and that inexpert use of leather dressing does more harm than good. Studies have shown that leather dressing can cause the leather to dry out over time. Leather may become stiffer, accompanied by darkening or surface staining. If too much dressing is applied too frequently, the surface of the leather may become sticky and attract dust and the oil stains and deteriorates the paper.
Consolidants like Klucel G (food-grade) can be applied by book conservators to bind dry rotted leather and keep it from offsetting onto other books or textblocks. For handling purposes, polyester film jackets can be made for books.
Will the Library of Congress restore or appraise my books?
The Library of Congress was established by a mandate of Congress that stipulated that the institution preserve and maintain its collection only. To find a conservator to treat damaged books and other valuable materials, consult the free referral service of The Foundation of the American Institute for Conservation (FAIC):
The Foundation of the American Institute for Conservation (FAIC)
1156 15th Street, NW, Suite 320
Washington, DC 20005-1714
202-452-9545
202-452-9328 (fax)
info@aic-faic.orgProfessional book appraisers and most book sellers will appraise and evaluate book materials. The Antiquarian Booksellers Association of America (ABAA) publishes an annual membership directory with addresses, phone numbers and area specialties such as early printed books or art and music. This directory is available from ABAA, 50 Rockefeller Plaza, New York, NY 10020.
Will the Library of Congress deacidify my book collections?
The Library is prohibited by law from working on privately owned collections and does not have the equipment necessary to perform such procedures. There are commercial deacidification vendors available, who are quite willing to handle private collections and small quantities of books as needed by the general public.
What if I have other questions about preservation of library and archives materials?
Contact the Preservation Directorate:
Preservation Directorate
Library of Congress
101 Independence Ave.
Washington, D.C. 20540-4500
Telephone 202-707-5213
FAX 202-707-3434
via our online form: Ask a Librarian.The preservation procedures described here have been used by the Library of Congress in the care of its collections and are considered suitable by the Library as described; however, the Library will not be responsible for damage to your collection should damage result from the use of these procedures.