Caring for paper collections
Paper appears in museum collections in many forms. Museums need to think carefully about how to care for paper collections and preserve them for future generations. For advice on caring for photographs, read our separate guide.
Threats to paper collections
Paper can be seriously and irreparably damaged in certain conditions.
Your paper collections could be affected by:
- Environmental factors, including fluctuating relative humidity, temperature, light and air pollution
- Materials that come into direct contact with the objects, in either storage or display
- The material quality of the object itself
In unfavourable conditions paper can become discoloured, dog-eared, or grow brittle. Paper is also subject to tears, abrasion, creases, stains, and the fading of ink and pigments. However, these issues can be prevented with a few simple improvements to display and storage conditions.
Below are examples of potential threats and conditions necessary to preserve paper:
- 45 – 65%
- Minimal fluctuations
- 10 – 20 ˚C
- Minimal fluctuations
- No light in storage
- When on display, maximum of 50 lux visible light
- Maximum of 10 microwatts per lumen of UV radiation
- Limited display periods
- Reduced particulate pollution
- Reduced gaseous pollution
- Pest control established in the museum building
- Systems that help people handle paper objects safely
- Barriers for more sensitives items that cannot be handled
- Must be chemically inert
- All the above conditions maintained to slow down deterioration
Relative humidity and temperature
Paper can be damaged or weakened by changing levels of relative humidity and temperature. When humidity is high, paper can become discoloured and lose flexibility.
Store paper in cool, dry places – avoid using basements or attics for display and storage. Take precautionary steps such as installing insulation, low level heating, or dehumidifiers in rooms that are naturally humid.
Our guide to lighting your displays provides details on how to reduce light damage. Light can fade inks and watercolours on paper, especially over extended periods of time or under high intensity. Store all paper items in the dark to avoid this.
There are precautions you can take to minimise light damage when displaying paper. Pay particular attention to ultraviolet (UV) radiation, which is present in all light but is unnecessary for viewing items.
- Expose paper to light for only 100,000 lux hours a year. Remove the item from display once it exceeds that time, or carefully turn pages regularly if the paper item is a book.
- Rotate paper items in and out of storage to reduce exposure hours.
- Block out all light outside of visitor hours.
- Limit the amount of daylight in a room as artificial light is easier to control.
- Put in anti-UV radiation precautions such as laminated glass or UV-absorbing filters.
Air often carries pollutants that can affect paper. Dust contains a mixture of many elements that could damage paper over time, dust can be difficult to remove from paper. Polluting gases, such as nitrogen dioxide and sulphur dioxide can also discolour paper.
Dangerous gases are produced by various sources, including:
- Vehicle emissions
- Wood and wood finishes
- Newly applied oil-based paints
- Poor quality paper products
- Some types of plastics, especially cellulose nitrate and poor quality foams
- Poorly processed photographic materials
- Photocopy machines
However, it’s possible to tackle airborne pollutants. Dust levels can be reduced by having well-sealed doors, windows, and display cases. General cleanliness and the use of covers over stored items can also minimise the spread of dust.
For polluting gases, identify any harmful materials and remove them from the room. Alternatively, use storage and packaging solutions made from materials such as MicroChamber®, a form of paper which contains molecular sieves. These materials trap specific molecules and are no more expensive than other quality storage materials.
Paper is less vulnerable to pests than textiles and some other materials in your collection. However, book lice and silverfish may still pose a threat, and pests should be anticipated when preparing paper displays. You should also be aware of mice and flies, as they can damage or destroy paper items.
Keep paper objects in cool and dry environments to avoid pests and monitor insect activity using sticky traps. Avoid wooden frames or boxes, as they can harbour woodworm. Contact conservators the moment you identify a pest problem.
Storage and display
You should plan ahead when preparing paper for storage or putting it on display. You could keep paper items in small bundles, inside high-quality sleeves, acid-free card folders, and large boxes or drawers.
Three-dimensional objects such as paper models require more thought (and plenty of acid-free tissue) when being stored. Make sure they don’t get crushed.
Degraded or damaged paper, large works, and fragile media are hard to handle safely. Museum staff and volunteers should receive training on how to handle paper items correctly and carry out practical procedures.
Here are some basic guidelines on dealing with paper objects:
- Ensure that there’s access to the correct facilities for safe work, including clean surfaces and basins for regular hand-washing.
- Use small weights to weigh down sheets of paper.
- Storerooms and cabinets should be clearly labelled.
- Items should be handled as little as possible.
- Label items using HB and 2B pencils or waterproof ink with fine-nibbed pens. Never use biros or felt pens.
- Never use Sellotape. For adhesives, use acid-free gummed paper or linen tapes.
Any materials in direct contact with paper items need to be high quality. If they’re not, damaging substances can transfer onto your paper items and cause discolouration, staining, and embrittlement.
- Wood pulp papers and card
- Wood, MDF and painted surfaces
- Polyvinyl chloride (PVC) plastic sleeves
- Paperclips, elastic bands, staples, Post-it notes, self-adhesive tapes and labels
- Dry mount adhesive
Invest in high quality materials. They may cost a little more, but they save you the expense of trying to restore damaged items and effectively preserve your collections. Paper, card, and plastic storage solutions can be purchased from dedicated conservation suppliers. Paper and card can be easily labelled and are often cheaper than plastic. However, using transparent plastics for storage creates the opportunity to view paper items minimal handling. Avoid using plastics on loose media such as charcoal, as static can remove loose media from the paper.
Qualities of good paper:
- Made from 100% cotton fibres or high-percentage of alpha cellulose fibres
- May be buffered or unbuffered
- Contains molecular sieves to trap airborne pollutants
Qualities of good plastics:
- Free from plasticisers and coatings
Some paper objects in your collection may be made from unstable materials which can deteriorate quickly. Modern newspapers, cheap paperback books, and faxes on thermally treated paper will degrade faster than other objects. A cool, dry environment will slow down this decay, as will conservation-grade display cases. Handle these objects infrequently and make copies before they deteriorate entirely.