Looking after archives

Documents

There are many easy ways to help preserve the archives of individuals or organisations. You do not need to be an expert or spend a lot of money on archival quality materials

  • To store documents, aim for a cool to cold atmosphere, dry rather than damp, but not over-dry. Avoid centrally-heated rooms and fluctuations in temperature and humidity. Aim for good ventilation. Bear in mind potential hazards such as pipes which might burst in winter
  • Try to avoid exposure to light (especially with photographs), dust, pollutants, rodents and insects
  • Avoid acidic and plastic packaging materials. Avoid rubber bands, glue and glued flaps, sellotape, paper clips, staples and drawing pins. Tie with tape rather than thin string or cord
  • Ensure you support documents, tied in bundles or within folders and boxes, as necessary
  • Store large volumes flat; avoid pulling volumes from the shelf by their headcaps
  • Store newscuttings in inert polyester, or photocopy newscuttings onto acid-free paper
  • Handle documents with clean hands, with care and as little as possible, especially fragile ones
  • Avoid folding, leaning or writing on documents. Use pencil when making notes from documents (ink has a nasty habit of attaching itself to the wrong place!)
  • Don't store cellulose nitrate based film (all 35mm film and all photo negatives made before c1952). It is very unstable and in extreme cases can self-ignite. Take it to your local record office for copying or advice
  • Take particular care with photographs
  • Be alert to acetic acid decay or 'vinegar syndrome' in photographic negatives/film. You can identify this by the strong vinegar smell. If detected, avoid breathing the fumes, isolate the affected material and seek specialist help as a priority. The noxious fumes are a health hazard
  • Be alert to mould growth (also a health hazard). If found, do not touch by hand or breathe in mould spores (use gloves and a dust mask). Seek specialist help as a priority
  • Don't attempt to repair documents yourself. Seek the advice of a skilled archive conservator (e.g. at/ via your local record office)
  • Consider depositing your original documents in your local record office and using copies. Seek advice from your local record office or archives support organisation (e.g. Hampshire Archives Trust)

Photographs

  • Store in a cool, dry and stable environment, avoiding light, dust, pollutants, rodents and insects
  • Take particular care with glass plates, ensuring they do not break
  • Ensure shelves/cabinets are stainless steel or stove-enamelled metal, not wood. Make sure are strong enough to bear the weight of photographic materials
  • Minimise the possibility of movement of photographic images within drawers/shelves. Store glass plates on static shelving
  • Use well-fitting storage products. Do not overfill but ensure you support photographic images
  • Store like with like, format-wise and size-wise
  • Never stack glass plates. Store them vertically on edge along their longest side, well-supported and individually wrapped in photographic quality storage paper (eg tradename Silversafe) with 4-flap enclosures
  • Sandwich broken/damaged glass plates between two pieces of glass or acid-, sulphur- and lignin-free board. Lay them flat, mark 'damaged material' and seek the advice of a specialist conservator
  • Avoid acidic and plastic, polythene, or PVC packaging materials. Also alkaline-buffered pulp boards and papers, glassine, woodpulp derivatives or coloured enclosures. Try not to use rubber bands, glue and glued flaps, sellotape, paper clips, staples and drawing pins
  • Aim to package/mount items using inert polyester (tradenames: Mylar, Melinex) or rag non alkaline-buffered lignin- and sulphur-free paper (eg tradename Silversafe) and board
  • Aim to use archival quality packaging materials for photographic images, including albums and photographic mounting corners
  • Consider wearing cotton gloves when handling photographic materials. Otherwise handle with clean hands, one at a time, picking photographic images up at their edges. Avoid touching the surface of the image
  • Ensure you support outsized, large, delicate or damaged photographic images when handling them
  • If stuck together, never try to force two photographs apart; seek specialist help
  • Avoid polishing/cleaning smears from transparencies, negatives or glass plates. Avoid using sprays/ cleaning products
  • Use only 2B pencils for any writing on the reverse of prints; lay the print on a hard board before writing on the back
  • Don't store cellulose nitrate based negatives (made before c1952). These are very unstable and in extreme cases can self-ignite. Take them to your local record office for copying or advice
  • Be alert to acetic acid decay or 'vinegar syndrome'. You can identify this by the strong vinegar smell. If detected, avoid breathing the fumes, isolate the affected material and seek specialist help as a priority. The noxious fumes are a health hazard

Digital records

Digital archives can be born-digital, meaning created electronically on a computer or digital camera, such as text, databases or digital photographs. They can also be digital copies of items, such as scans of older photographs or posters; these are known as digital surrogates. It is harder to preserve digital material than paper and parchment.

To preserve digital material, we suggest that you create or preserve it in a suitable format. It is best to be aware of these formats before you start. Our guidelines will help you choose an appropriate format.

Our Digital Preservation Policy describes our approach to digital archives.

Film and sound

Cinefilms, video and sound recordings are mostly made of quite fragile polymers (plastics) and, as such, have only a finite life. Some will take longer than others to decay and this usually depends upon how well they are looked after. Keeping such materials in good condition needs particularly careful handling and storage. Master material should not be used for research or display and stored separately from copies. Old, non-maintained equipment can damage items.

Store film and sound recordings in their proper containers in dark, cold, constant, and (not too) dry conditions. Store away from pipes, heaters and radiators, sinks, windows, electrical appliances and concrete floors. Excessive temperatures, humidity and dirt can destroy films and sound recordings. So can fire, flood and contamination from insects and rodents.

Reasonable temperatures for long term storage lie in the range 10-16°C (50-60°F) within a low relative humidity of 50-55%. Official recommendations for archival storage are more stringent and depend upon the type and format of material concerned. Most colour films will fade unless kept below 2°C, for example.

Things to look out for

  • Tapes which 'squeal' or stick when replayed. These may have 'sticky tape syndrome'. This is where damp has affected the binder between the magnetic coating and base and migrated to the tape surface. It may be chemically deteriorating and need specialist conservation treatment before copying
  • Light - the ultraviolet end of the spectrum can cause breakdown in polymers, so you must protect film and sound recordings from it in storage
  • Pollutants like dirt, dust, fingermarks and atmospheric pollution. You can reduce these with clean storage, careful handling, good packaging (but not totally sealed). Avoid smoking, eating or drinking nearby, and using clean equipment
  • Shedding tape coatings. This often shows as missing signals when playing tapes (called 'drop out' on video tapes), or a build up of oxide on tape heads and guide rollers. The cause may be the tape itself or the replay equipment. This affects some tapes after a few years from manufacture, so this is not always due to old age
  • Shrinkage is a sign of old age, but not the only one. Central heating can dry out film and sound recordings. It can also cause other problems like warping, cracked surfaces on discs and splices which come undone. These will need careful repairs and conservation treatment. Affected items should not be replayed or projected, because of the damage that may result
  • CDs & DVDs are vulnerable to pollutants and light, even adhesive labels and pen marks, in the long term. To keep the contents for archival purposes, use discs with a gold metal reflective layer. Store on end not flat, and use 'jewel cases' or special conservation grade envelopes. Best conditions: 18°C at 40% relative humidity

Warning

Cinefilm on a cellulose nitrate base - 35mm film made before 1952 - is unstable and highly flammable. It is particularly dangerous when decaying, especially in the final powdery state. In extreme cases it can self-ignite, and burns with a very fierce flame, giving off highly toxic gases. You should not store it in a private house, museum or library. You should duplicate it onto safety-base film. Then lodge the nitrate original in a specialist store, dispose of it by a licensed firm or take it to the 'hazardous household waste' container at your recycling centre.

Other cinefilms are on safety bases and are stable unless damp conditions trigger mould or acetic acid decay. The latter is better known as 'vinegar syndrome', because of its distinctive smell. It affects films on acetate safety bases but not polyester. The gases given off are hazardous to health and can 'infect' other films and tapes in the vicinity.

Mould will grow on film and sound recordings. It attacks emulsions, tape binders, plastic reels and cassette housings, gramophone discs and wax cylinders. Wear gloves and dust mask when handling. The growth looks like dull spots. Enclosures like plastic bags and sealed containers, which do not allow the plastics to 'breathe', encourage it. If caught early, specialist conservation treatment can help correct this problem. But make copies as soon as possible thereafter.