Identifying Film
Motion picture film can be made of various materials and by different processes and both material and process inform storage, handling, and duplication recommendations.
Cellulose nitrate and cellulose acetate film bases are chemically unstable and require special action to minimize the risk of total loss as well as the risk of collateral damage to surrounding collections.
The following references are useful for identifying film:
- Conservation OnLine, Motion Picture Film Preservation (A portal that covers a range of preservation topics for motion picture film, including identification, handling, storage, standards, and nitrate and acetate deterioration and management)
- Monique Fischer, A Short Guide to Film Base Photographic Materials: Identification, Care, and Duplication. Northeast Document Conservation Center Preservation Leaflet 5.1.
- Monique Fischer and Andrew Robb. Guidelines for Care & Identification of Film-Base Photographic Materials. Conservation Online. 1993.
General Care and Handling of Motion Picture Film
The following general guidelines pertain to the handling of polyester-based film; cellulose nitrate and cellulose acetate films require special protocols.
Take proper care when handling film by:
- Have clean hands and use a new pair of nitrile gloves (using clean cotton gloves is better than having fingerprints on the film, but cotton fibers are abrasive and can scratch the emulsion)
- Store and handle film in a clean environment; minimize exposure to dust and airborne particulates
- Keep food and drink away
- Do not touch the face of the film, including the emulsion; if film must be directly handled, handle film only by the edge
- Keep playback equipment clean and well maintained
- Use duplicate films for access when possible and outfit the projector with a low-heat bulb
- Allow materials from cool storage to acclimate to room temperature over a period of at least 24 hours before playing back
General Guidelines for the Proper Storage of Motion Picture Film
Motion picture films and especially the silver particles or color dyes that constitute the image are highly sensitive to inappropriate environmental conditions; good storage is arguably the best preservation measure one can take:
- A relatively dry (30-50% relative humidity), cool (room temperature or below), clean, and stable environment (avoid attics, basements, and other locations with high risk of leaks and environmental extremes)
- Distance from radiators and vents
- Wound securely (not loose and not too tight), evenly, and neatly with a generous (e.g., 3") center diameter, emulsion side out
- Protective enclosures* that physically support the film, block all light, and minimize exposure to dust and airborne (particularly sulfur-containing) atmospheric pollutants
*Storage materials (cores, reels, and enclosures such as boxes or cans) made from acceptable plastics (polypropylene or polyethylene), preservation-quality cardboard, or noncorroding metal that pass the Photographic Activity Test. Some preservation suppliers.
Dealing with Nitrate Film
Nitrate-base film is highly flammable (can self-ignite at ambient temperatures around 100 degrees F), cannot be extinguished once ignited, and is therefore a serious a fire hazard. Quantities of nitrate film in excess of 25 pounds are subject to storage and handling standards prescribed by the National Fire Protection Association (NFPA 40: Standard for the Storage and Handling of Cellulose Nitrate Film 
).
Immediate actions for nitrate film:
- Keep the ambient temperature as cool as possible and always below 70 degrees F; freezing is recommended
- Keep the relative humidity between 30-40%
- Do not expose film to sources of heat
- Remove from non-ventilated storage containers; use ventilated storage containers; keep storage area well ventilated
- Isolate from other collection items (nitrate film can emit gases that are harmful to humans and to other collection items)
- Consider digitizing
and disposing
Further Information on Nitrate Film
Kodak, Storage and Handling of Processed Nitrate Film
National Park Service, Conserve O Gram, Caring for Cellulose Nitrate Film [PDF: 249 KB / 4 pp.] and Disposal Of Cellulose Nitrate Film [PDF: 240 KB / 4 pp.]
Dealing with Cellulose Acetate Film
Cellulose acetate film, also known as "safety" film, is not flammable like cellulose nitrate film, but it is also unstable and undergoes an autocatalytic degradation mechanism that results in embrittlement, shrinkage, and eventual total loss of the image. Like nitrate film, degrading cellulose acetate produces gases that are harmful to other collection items.
Necessary Actions for Acetate Film
- Keep the ambient temperature as cool as possible; freezing is recommended if degradation has already started
- Keep the relative humidity between 30-50%
- Remove from non-ventilated storage containers; use ventilated storage containers; keep storage area well ventilated
- Isolate from other collection items
References
Edward Blasko, Benjamin A. Luccitti, Susan F. Morris, ed., The Book of Film Care, (Rochester, NY: Motion Picture and Television Image, Eastman Kodak Co., 1992).
Nicolette Bromberg, Hannah Palin, and Libby Burke, Washington State Film Preservation Manual: Low-cost & No-cost Suggestions to Care for Your Film [PDF: 821 KB / 37 pp.]
Paul J. Gordon, ed. The Book of Film Care (Rochester, NY: Eastman Kodak, 1983).
Paul Read and Mark-Paul Meyer, Restoration of Motion Picture Film (Oxford: Butterworth-Heinemann, 2000).
Conservation OnLine. Motion Picture Film Preservation.
Film Forever, The Home Film Preservation Guide
Image Permanence Institute, IPI Media Storage: Quick Reference [PDF: 2 MB /9 pp.]
National Film Preservation Foundation, Preservation Basics
Northeast Document Conservation Center, Storage and Handling of Media Collections
National Audio-Visual Conservation Center
Audio-Visual Conservation at the Library of Congress.
The preservation procedures described here have been used by the Library of Congress in the care of its collections and are considered suitable by the Library as described; however, the Library will not be responsible for damage to your collections should damage result from the use of these procedures.
