The conservation of books and documents

1. What are the proper conditions in which to store books and documents at home?

The recommended climate for paper in libraries, archives and museums is a more or less stable temperature of about 18 degrees centigrade and a relative humidity (RH) between 50 and 55%. This 'ideal' climate may be difficult to obtain at home. However, it is possible to create as good a climate as possible by taking a few simple measures: try to compensate for the dry air radiated by central heating by using a simple humidifier and thus raise the RH somewhat. Also, try to keep the temperature at 21 degrees at the most. During summer, and especially when outside temperatures are high, keep doors, windows and curtains closed as much as possible. This will keep temperatures inside relatively low. Never hang your objects on paper on damp walls, and do not place bookcases against such a wall. Do not install bookshelves next to heat sources, and prevent direct sunlight on bookcases, prints, drawings, maps etc. It is also not recommended to expose framed objects on paper to spotlights. Both sunlight and artificial light contain UV-radiation and release heat, both detrimental for paper.

2. What are the best materials to store your documents in?

Never use synthetic sleeves that contain plasticizers. Avoid cardboard folders and boxes which contain acids or lignin (ground wood). Store your documents exclusively in materials that were made for this purpose. Remove all paperclips and staples, as these will rust and damage the paper. Take care, when having your prints and drawings framed, that acid free mounting board is used.

3. How to use an old book?

Never use force to open a book flat when it does not do so by itself. In such a case it is advisable to open the book v-shaped and support it by using two rolled -up tea cloths. Be mindful to always open a heavy volume in the middle, and only after it is put to rest in this way turn to the desired page.

4. How to prevent damaging a book when taking it off the shelf?

Never take a book off the shelf by pulling the back (spine). Slide it forward on the shelf or move the adjacent books a bit back. Providing the shelf is not overcrowded, this procedure will allow you to remove your book without inflicting damage.

5. Is photocopying harmful to books?

The light of modern photocopiers does not damage the paper when making a single photocopy. Damage can however occur to the construction of books when photocopying is not done carefully. In any case do not press an old book flat against the glass plate of the copier. Fortunately there are more and more copiers that allow books to be copied v-shaped.

6. What to use on leather and parchment bookbindings?

Conservation of bookbindings is a procedure that can only be carried out professionally by specialists. In spite of the best of intentions severe damage can be inflicted upon leather and parchment when unsuitable substances are applied to your bookbindings. Therefore, never use a household-cleaning product to remove stains, and never apply fats or waxes like beeswax, shoepolish or linseed oil to bookbindings.

7. How to repair tears in paper?

All self-adhesive repair tapes have serious drawbacks: the adhesive may damage the paper in a number of ways. As with the conservation of leather and parchment bookbindings, professional help should be sought.

8. Should my books be deacidified?

When paper is too acid and also contains lignin (ground wood paper) it will eventually yellow and weaken and become vulnerable to tearing. Eventually, this kind of paper will become brittle to such an extent that it can no longer be used. This problem is paramount in 19th and 20th century paper, and notably in the common pocket book and in newspaper. Unfavourable storing conditions can aggravate this degradation process. For acid paper with a high lignin content deacidification is recommended. As a general rule, books and documents dating from before the 1800's do not need deacidification.

9. What to do with a book that is infested by insects or mould?

Infestation by mould is the greatest threat to wet or damp books. Wet books should therefore be dried as soon as possible. In case of only a few wet books the simplest procedure is to fan them open and use a ventilator to create a draught. It is important to thoroughly ventilate the room where all this is taking place, for example by opening a window. Large amounts of water damaged books should be deep frozen as soon as possible and at a later stage be freeze-dried: consult a professional firm that specialises in this kind of work. Modern coated papers that have been water damaged will in most cases suffer irreparable damage. Another form of this so-called biodegradation is insect damage. This phenomenon is as much related to climatic conditions (see 1) as to hygienic factors. For the eradication of insects specialised firms have developed effective procedures. An effective emergency treatment, for example for single books, is wrapping it in a plastic bag with a house hold pesticide in the form of for example a pet flea collar or an insect strip. A period of about 14 days should suffice. Take care not to bring your book in direct contact with the pesticide. Always check carefully any book that spent a long period of time in a market or cellar or on an attic before giving it a place among your other books. It may be inhabited by insects or mould.

10 Where can I have my books restored and get some professional advice?

To have your book or document restored in a professional way you should contact a qualified book- and paper restorer in your city or area. To find a professional restorer in the Netherlands contact the Restauratoren Register in Amsterdam. To obtain advice on conservation and information about suppliers of products and services, contact either the Koninklijke Bibliotheek (see address below) or the department of Information & Research of the in Amsterdam.

Compiled by the Department of Conservation & Optical Technologies
Illustrations: H.J. Porck
Information via Contact us, telephone +31703140567