Motion picture film can be either black and white, or colour. It comes in a range of gauges (or widths). The most common are 8 mm, 16 mm and 35 mm.

A number of different components make up motion picture film. These include:

• negatives
• magnetic film soundtracks
• projection or release prints

Motion picture film consists of a thin plastic base coated with a layer of gelatine emulsion. The emulsion contains the image, made from either silver particles (in black and white film) or colour dyes (in colour film). The emulsion is the matte side and the base is the shiny side of the film.

There are three types of bases used to make motion picture film:

• Early filmmakers produced motion picture film on a cellulose nitrate base. This type of film is highly flammable. Nitrate-based film was widely used until the 1940s.
• Motion picture film made with a cellulose triacetate base is known as acetate or ‘safety’ film. It dates from the 1940s, and does not have the combustible qualities of cellulose nitrate motion picture film.
• Polyester-based motion picture film is thinner and stronger than acetate film. It cannot be torn.

All materials degrade over time. Although this deterioration is inevitable, correct handling and care can slow down its progress.

Motion picture film is at risk from three types of deterioration: chemical disintegration, biological decay and mechanical damage.

Chemical disintegration

The different plastics used to construct motion picture film are at risk from different types of chemical disintegration.

• Cellulose nitrate film is very unstable. It can react with water in the air to form nitric acid. As it deteriorates, nitrate film develops a sticky or greasy surface, a dark yellow or brown all over staining, and a strong bitter or acrid smell. It can self-ignite in some circumstances, and is difficult to extinguish once it starts to burn.
• Cellulose triacetate film is vulnerable to ‘vinegar syndrome’, where the plastic reacts with water in the air to form acetic acid. This produces a vinegar smell, which gives the reaction its name. Vinegar syndrome-affected film shrinks, starts to ‘wave’ so that the film will not lie flat, and develops a white powder on the edges. The emulsion cracks so that the image appears fragmented, and can flake off from the base.

Colour motion picture film is also at risk from colour fading.

Biological decay

Film stored in warm, humid conditions is likely to develop mould. This type of decay can result in serious damage to the emulsion layer of motion picture film, and therefore the images recorded on the film.

Mechanical damage

Motion picture film is at risk of damage from being played or recorded.

• Mishandling motion picture film during winding or projection can tear or break motion picture film.
• Winding or projection can cause old splices to come undone.
• Improper threading of motion picture film during projection can result in perforation damage.
• Contact with dirt or other contaminants can scratch motion picture film.

As with any item, correct handling and care of motion picture film will give items the best chance at longevity.

Handling

• Film is fragile. Handle all motion picture films with care.
• Handle film by the edges, and avoid touching the emulsion. This image-holding layer of the film is easily damaged.
• Return films to their protective packaging when finished using them.
• Ensure that all playback and recording equipment is clean and in good working order before using it, to minimise mechanical damage.

Nitrate-based film and acetate film affected by vinegar syndrome pose a threat to health and safety. Care should be taken when handling such film.

Nitrate-based film is classified as a hazardous material. It must be stored separately from other collection materials, in a designated area that firefighters can identify. Although the National Archives does not store this type of film, the Archives can be contacted for further advice.

The fumes produced by both deteriorating nitrate film and vinegar syndrome-affected film are toxic. If a sweet odour or vinegar smell are coming from a film, do not open the can. Exposure to these gases can cause throat, eye and skin irritations.

Protective packaging

• Store motion picture film in clean, acid-free plastic cans to protect the records from dust, dirt and other contaminants.
• Before enclosing motion picture film in protective packaging, ensure that the item is free from dust, mould and other contaminants.
• Wind motion picture film as flat as possible around the core or reel to a medium tension, so that the film can ‘breathe’ but is not loose in the can. Any ridges or irregularities in the wind will expose the film to possible damage. The end of the role should be taped down to ensure the film does not unwind or unravel.
• Label every film can clearly and prominently to ensure easy identification and protect the item from further handling.

Storage environment

It is very important to store motion picture film in an area free from fluctuating temperature and relative humidity levels.

Warm and humid conditions, as well as changing temperature and relative humidity levels, can cause chemical disintegration and biological decay. Storing motion picture film in cool, dry and stable conditions may prevent or slow down the progress of these types of deterioration.

Cold storage (10°C and below) is the only way to increase the stability of motion picture films which have started to deteriorate. Cold storage is also the best way of keeping unblemished films in good condition. Ideally:

• black and white film should be kept in temperatures between 15°C and 18°C, and at 35% relative humidity
• colour film should be kept in low temperatures (less than 8°C) and at 35% relative humidity.

If cold storage is not possible, the storage area should be kept clean and be well ventilated to prevent the build up of acidic gases produced by vinegar syndrome affected film. These gases speed up the progress of this type of deterioration.

Materials degrade quicker when exposed to ultraviolet light. Fluorescent tubes, which are low in ultraviolet light, should be used wherever possible in storage areas. Lights should be turned off whenever possible. Storage areas should not have windows, but if they do they should be covered with curtains or blinds.

Storage equipment

Store motion picture film horizontally on shelves above the floor (to prevent water damage in case of flooding) and sheltered from the ceiling (to prevent water damage from fire sprinklers).
Store motion picture film on coated metal shelving. Wooden shelving can release harmful vapours, contribute to the spread of fire and harbour insects.

Copying

To minimise deterioration due to handling and use, make copies of important and frequently used films for reference purposes.

Video and DVD production bureaus which undertake film to video and film to DVD copying are located throughout Australia. Contact details for these service providers may be found in local telephone directories. 

Contact the Agency Service Centre if you require further advice on protecting and handling motion picture film.

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