Paper-based materials make up a large portion of our cultural heritage and they take many forms, such as books, artworks, maps and letters. Paper is a relatively fragile substance, however, there are ways that you can preserve its longevity. Much of the damage to paper materials occurs through poor handling, storage and display. For example, mould can be the result of damp storage conditions, and various mounting materials can cause staining and discolouration.
Some general recommendations are given below to minimise such damage.
• Try to provide as stable conditions as possible in the storage area. The optimum storage conditions are 18–22°C and 45–55% relative humidity. Higher temperatures and humidities will speed up the degradation of the paper and encourage mould growth. Fluctuations cause distortions and subsequent damage to paper items.
• Avoid using an attic or basement as a storage area. Conditions in these areas fluctuate greatly. If possible, use a storage site in the centre of a building. These areas experience less fluctuations in temperature and humidity.
• Keep light to a minimum. Avoid strong light sources and direct sunlight, as these will accelerate the degradation and fading processes.
• Keep away from heaters, fireplaces and other sources of heat.
• Avoid contact with bathroom, kitchen, laundry and external walls, as humidity in these areas fluctuates.
• Keep storage areas clean and well ventilated to avoid pests and mould growth.
• Check the condition of an item before placing it in storage. Sort items into groups, according to their condition, media and format.
• Place valuable, fragile, and items in need of repair in archival boxes/envelopes, or use acid-free paper to wrap the items. These will provide additional protection, as well as keeping pieces together.
• Do not repair items with sticky tape. Any self- adhesive tape, even ‘magic invisible mending tape’ can cause harm in the long term. If an item has been damaged by sticky tape, seek the advice of a professional conservator.
• Gently dust and clean the items using a soft-bristle brush (an unused shaving brush is ideal). This will deter insects and mould growth.
• When standing items up on bookcases, do not pack them too tightly; this is to prevent using one finger at the top of the spine as a lever to remove items from the shelf. This will reduce the risk of damaging the binding.
• Lay items flat in archival (acid-free) boxes, or use ordinary boxes lined with acid-free paper. Valuable or fragile items should be individually wrapped or interleaved.
• Place boxes off the ground (e.g. on shelves) to allow good air circulation and prevent damage in the event of a flood.
• Seal boxes with packing tape to keep pests out.
• Ensure that there are no overhead pipes in the area, as these can drip. Placing plastic over the boxes may protect them from this, however, it will restrict air circulation and may encourage mould growth.
• If using pest strips, insect traps and pesticides ensure that these do not come in direct contact with the items.
• Air musty books in a sunny area before packing, brush surface dirt off with a soft brush (do this outside).
• Check for insects and unhatched eggs. Remove these with a brush before storage.
• Wrap leather-bound books in archival paper to prevent transfer of stains to other items.
• Use several smaller boxes instead of one large one. This creates more space for circulation of air, which decreases the chances of mould growth.
• Shelve books upright so that they are supported on either side. Shelve books of a similar size together. If the binding is damaged or fragile, you may keep the book flat as this relieves stress on the spine.
• Do not push books to the rear of a shelf. The space between the book, wall and shelf provides air circulation space.
Artworks and documents
• Store artworks and documents in folders or keep them mounted and framed. In the case of works with fragile or delicate surfaces such as unfixed charcoal or chalk drawings, they should be mounted to avoid abrasion and smudging.
• For long-term protection, mounts should be made from 100% rag, acid-free, alkaline buffered mountboard. This is sometimes called ‘museum board’. The mount should have front and back boards and the item should be hinged to the backboard. Conservators prefer to use Japanese paper hinges and wheat starch paste because they are stable and long lasting.
• Frames can be fitted with glass or perspex. Items with loose powdery media should be framed with glass, as perspex has a static charge. In all cases there should be no contact between the item and the glazing.
• Keep frames off the floor. Stand upright on blocks or pieces of foam if shelves are not available.
• Avoid rolling oversize items. If this is unavoidable, roll the item onto a wide diameter (at least 10 cm) cardboard tube, which has been covered with Tyvek™ or acid-free tissue. Wrap the rolled item with Tyvek™ or acid-free tissue.
• Store documents and letters flat and unfolded in acid-free folders or use polypropylene or polyester bags. These can then be placed in boxes.
Newspapers and faxes
Due to the nature of paper used for faxes and newspapers, these have very short life spans. To preserve the information content of such items it is best to copy them. The techniques available include photocopying onto archival (acid-free) paper and microfilming. A separate fact sheet is available on storing newspapers.
• It is important to have clean, dry hands or wear gloves when handling paper based materials because paper easily absorbs skin oil and perspiration, which can cause staining and degradation.
• When handling and transporting unframed artworks and documents, use a thick support paper underneath or place your item inside a folder.
• When carrying a framed work, grip both sides of the frame.
• If a valuable or fragile item is going to be handled frequently, it might be a good idea to create a duplicate. This way the duplicate can be referred to and the original stored away for preservation.
We are unable to give specific advice on conservation treatment of items. The advice we are able to give is limited to what we understand to be ethical and safe for people and items. For treatment purposes we recommend that you contact a professional conservator, who will be able to assess each individual item and give it appropriate treatment. A conservator will charge a fee.