Film preservation, or film restoration, describes a series of ongoing efforts among film historians, archivists, museums, cinematheques, and non-profit organizations to rescue decaying film stock and preserve the images which they contain. In the widest sense, preservation nowadays assures that a movie will continue to exist in as close to its original form as possible.
For many years the term "preservation" was synonymous with "duplication" of film. The goal of a preservationist was to create a durable copy without any significant loss of quality. In more modern terms, film preservation now includes the concepts of handling, duplication, storage, and access. The archivist seeks to protect the film and share the content with the public.
Film preservation is not to be confused with film revisionism, in which long-completed films are subjected to outtakes never previously seen being inserted, newly inserted music scores or sound effects being added, black-and-white film being colorized or converted to Dolby stereo, or minor edits and other cosmetic changes being made.
By the 1980s, it was becoming apparent that the collections of motion picture heritage were at risk of becoming lost. Not only was the preservation of nitrate film an ongoing problem, but the discovery that safety film, used as a replacement for the more volatile nitrate stock, was beginning to be affected by a unique form of decay known as "vinegar syndrome", and color film manufactured, in particular, by Eastman Kodak, was found to be at risk of fading. At that time, the best known solution was to duplicate the original film onto a more secure medium.
90 percent of all American silent films made before 1929 and 50 percent of American sound films made before 1950 are lost films.
Although institutional practices of film preservation date back to the 1930s, the field received an official status only in 1980, when UNESCO recognized "moving images" as an integral part of the world's cultural heritage.
The great majority of films made in the silent era are now considered lost forever. Movies of the first half of the 20th century were filmed on an unstable, highly flammable cellulose nitrate film base, which required careful storage to slow its inevitable process of decomposition over time. Most films made on nitrate stock were not preserved; over the years, their negatives and prints crumbled into powder or dust. Many of them were recycled for their silver content, or destroyed in studio or vault fires. The largest cause, however, was intentional destruction. As film preservationist Robert A. Harris explains, "Most of the early films did not survive because of wholesale junking by the studios. There was no thought of ever saving these films. They simply needed vault space and the materials were expensive to house." Silent films had little or no commercial value after the advent of sound films in the 1930s, and as such, they were not kept. As a result, preserving the now rare silent films has been a high priority amongst film historians.
Because of the fragility of film stock, proper preservation of film usually involves storing the original negatives (if they have survived) and prints in climate-controlled facilities. The vast majority of films were not stored in this manner, which resulted in the widespread decay of film stocks.
The problem of film decay is not limited to films made on cellulose nitrate. Film industry researchers and specialists have found that color films (those made in the processes which replaced Technicolor) are also decaying at an increasingly rapid rate. A number of well-known films only exist as copies of original film productions or exhibition elements because the originals have decomposed beyond use. Cellulose acetate film, which was the initial replacement for nitrate, has been found to suffer from "vinegar syndrome". The ongoing preservation of color films is now presented with an issue, as low temperatures, which inhibit color fading, actually increase the effects of vinegar syndrome, while higher (normal room) temperatures cause color fading.
Film decay as an art form
In 2002, filmmaker Bill Morrison produced Decasia, a film solely based on fragments of old unrestored nitrate-based films in various states of decay and disrepair, providing a somewhat eerie aesthetic to the film. The film was paired together with a soundtrack composed by Michael Gordon, and performed by his orchestra. The footage used was from old newsreel & archive film, and was obtained by Morrison from several sources, such as the Fox Movietone Newsfilm Archives at the University of South Carolina, and the archives of the Museum of Modern Art.
Preservation through careful storage
The "preservation" of film usually refers to physical storage of the film in a climate-controlled vault, and sometimes to the actual repair and copying of the film element. Preservation is different from "restoration", as restoration is the act of returning the film to a version most faithful to its initial release to the public and often involves combining various fragments of film elements.
Film is best preserved by proper protection from external forces while in storage along with being under controlled temperatures. For most film materials, the Image Permanence Institute finds that storing film media in frozen temperatures, with RH between 30% and 50%, greatly extends its useful life. These measures inhibit deterioration better than any other methods and are a cheaper solution than replicating deteriorating films.
Preparing a film for preservation and restoration
In most cases, when a film is chosen for preservation or restoration work, new prints are created from the original camera negative or the composite restoration negative which is often made from a combination of elements for general screening.
The composite restoration negative is a compilation of duplicated sections of the best remaining material, recombined to approximate the original configuration of the original camera negative at some time in the film's release cycle, while the original camera negative is the remaining, edited, film negative that passed through the camera on the set. This original camera negative may, or may not, remain in original release form, depending upon number of subsequent re-releases after the initial release for theatrical exhibition.
In traditional photochemical restorations, image polarity considerations must be observed when recombining surviving materials and the final, lowest generation restoration master may be either a duplicate negative or a fine grain master positive.
Preservation elements, such as fine-grain master positives and duplicate printing negatives, are generated from this restoration master element to make both duplication masters and access projection prints available for future generations.
Film as archival medium
Film preservationists would prefer that the film images, whether restored through photochemical or digital processes, be eventually transferred to other film stock, because no digital media exists that has proven truly archival because of rapidly evolving and shifting data formats, while a well-developed and stored, modern film print can last upwards of 100 years.
While some in the archival community feel that conversion from film to a digital image results in a loss of quality that can make it more difficult to create a high-quality print based upon the digital image, digital imaging technology has become increasingly advanced to the point where 8K scanners can capture the full resolution of images filmed at as high as 65mm. 70mm IMAX has a resolution of 18K, which is the upper necessary limit for film capture in full resolution.
Of course, having an intermediate digital stage, followed by forming a new film master by lasering the digital results onto new film stock does represent an extra generation. So would an intermediate film master that was restored frame-by-frame by hand. The choice of film vs. digital restoration will be driven by the amount, if any, of restoration required, the taste and skill set of the restorer, and the economics of film restoration vs. digital restoration.
Digital as archival medium
Digital scanners as of 2014 can capture images as large as 65mm in full resolution. That is the typical image size on a traditional (as opposed to the IMAX process) 70mm film which used a portion of the film surface for its multitrack magnetic sound stripe. A 70mm print of a two and a half hour film as of 2012 ran upwards of $170,000. A hard disk capable of storing such a movie is a few hundred dollars. An archival optical disk will be less. The problem of having to transfer the data as new generations of equipment come along will continue, however, until true archival standards are put in place.
Digital film preservation
In the context of film preservation, the term "digital preservation" highlights the use of digital technology for the transfer of films from 8mm to 70mm in size to digital carriers, as well as all practices for ensuring the longevity and access to digitized or digitally born film materials. On purely technical and practical terms, digital film preservation stands for a domain specific subset of digital curation practices. Extensive technical literature on the subject can be found at the online library of the Presto Centre Project.
The aesthetic and ethical implications of the use of digital technology for film preservation are major subjects of debate. For instance, the senior curator of George Eastman House Paolo Cherchi Usai has decried the shift from analogue to digital preservation of film as ethically unacceptable, arguing, on philosophical terms, that the medium of film is an essential ontological precondition for the existence of cinema. More recently, the senior curator of EYE Film Institute Netherlands Giovanna Fossati has discussed the use of digital technologies for the restoration and preservation of film in a more optimistic way as a form of remediation of the cinematic medium, and has positively reflected on digital technologies' ability to broaden restoration possibilities, improve quality, and reduce costs. According to the cinema scholar Leo Enticknap, the views held by Usai and Fossati could be seen as representative of the two poles of the digital debate in film preservation. It should be kept in mind, however, that both Usai and Fossati's arguments are highly complex and nuanced, and likewise, the debate about the utility of digital technologies in film preservation is complex and continually evolving.
In 1935, New York's Museum of Modern Art began one of the earliest institutional attempts to collect and preserve motion pictures, obtaining original negatives of the Biograph and Edison companies, and the world's largest collection of D. W. Griffith films. The following year, Henri Langlois founded the Cinémathèque Française in Paris, which would become the world's largest international film collection.
For thousands of early silent films stored in the Library of Congress, mostly between 1894 and 1912, the only existing copies were printed on rolls of paper submitted as copyright registrations. For these, an optical printer was used to copy these images onto safety film stock, a project that began in 1947 and continues today. The Library hosts the National Film Preservation Board, whose National Film Registry annually selects 25 U.S. films "showcasing the range and diversity of American film heritage." The George Eastman House International Museum of Photography and Film was chartered in 1947 to collect, preserve and present the history of photography and film, and in 1996 opened the Louis B. Mayer Conservation Center, one of only four film conservation centers in the United States. The American Film Institute was founded in 1967 to train the next generation of filmmakers and preserve the American film heritage. Its collection now includes over 27,500 titles.
In 1978, Dawson City, Yukon Territory, Canada, a construction excavation inadvertently found a forgotten collection of more than 500 discarded films from the early 20th century that were buried in and preserved in the permafrost. This fortunate discovery was shared and moved to the United States' Library of Congress and Library and Archives Canada for transfer to safety stock and archiving. However, to move such highly flammable material such a distance ultimately required assistance from the Canadian Armed Forces to make the delivery to Ottawa. The story of this discovery as well as excerpts of these films can be seen in the 2016 documentary film, Dawson City: Frozen Time.
Another high-profile restoration by staff at the British Film Institute's National Film and Television Archive is the Mitchell and Kenyon collection, which consists almost entirely of actuality films commissioned by traveling fairground operators for showing at local fairgrounds or other venues across the UK in the early part of the twentieth century. The collection was stored for many decades in two large barrels following the winding-up of the firm, and was discovered in Blackburn in the early 1990s. The restored films now offer a unique social record of early 20th-century British life.
Individual preservationists who have contributed to the cause include Robert A. Harris and James Katz (Lawrence of Arabia, My Fair Lady, and several Alfred Hitchcock films), Michael Thau (Superman), and Kevin Brownlow (Intolerance and Napoleon). Other organizations, such as the UCLA Film and Television Archive, have also preserved and restored films; a major part of UCLA's work includes such projects as Becky Sharp and select Paramount/Famous Studios and Warner Bros. cartoons whose credits were once altered due to rights taken over by different entities.
In 1926 Will Hays asked for film studios to preserve their films by storing them at 40 degrees at low humidity in an Eastman Kodak process, so that "schoolboys in the year 3,000 and 4,000 A.D. may learn about us".
Beginning in the 1970s, Metro-Goldwyn-Mayer, aware that the original negatives to many of its Golden Age films had been destroyed in a fire, began a preservation program to restore and preserve all of its films by using whatever negatives survived, or, in many cases, the next best available elements (whether it be a fine-grain master positive or mint archival print). From the onset, it was determined that if some films had to be preserved, then it would have to be all of them. In 1986, when Ted Turner acquired MGM's library (which by then had included Warner Bros.' pre-1950,[nb 1] MGM's pre-May 1986, and a majority of the RKO Radio Pictures catalogs), he vowed to continue the preservation work MGM had started. Time Warner, the current owner of Turner Entertainment, continues this work today.
The cause for film preservation came to the forefront in the 1980s and early 1990s when such famous and influential film directors as Steven Spielberg and Martin Scorsese contributed to the cause. Spielberg became interested in film preservation when he went to view the master of his film Jaws, only to find that it had badly decomposed and deteriorated—a mere fifteen years after it had been filmed. Scorsese drew attention to the film industry's use of color-fading film stock through his use of black-and-white film stock in his 1980 film Raging Bull. His film, Hugo included a key scene in which many of film pioneer Georges Méliès' silent films are melted down and the raw material recycled as shoes; this was seen by many movie critics as "a passionate brief for film preservation wrapped in a fanciful tale of childhood intrigue and adventure."
Scorsese's concern about the need to save motion pictures of the past led him to create The Film Foundation, a non-profit organization dedicated to film preservation, in 1990. He was joined in this effort by fellow film makers who served on the foundation's board of directors—Woody Allen, Robert Altman, Francis Ford Coppola, Clint Eastwood, Stanley Kubrick, George Lucas, Sydney Pollack, Robert Redford, and Steven Spielberg. In 2006, Paul Thomas Anderson, Wes Anderson, Curtis Hanson, Peter Jackson, Ang Lee, and Alexander Payne were added to the board of directors of The Film Foundation, which is aligned with the Directors Guild of America.
By working in partnership with the leading film archives and studios, The Film Foundation has saved nearly 600 films, often restoring them to pristine condition. In many cases, original footage that had been excised—or censored by the Production Code in the U.S.—from the original negative, has been reinstated. In addition to the preservation, restoration, and presentation of classic cinema, the foundation teaches young people about film language and history through The Story of Movies, an educational program claimed to be "used by over 100,000 educators nationwide".
In the age of digital television, high definition television and DVD, film preservation and restoration has taken on commercial as well as historical importance, since audiences demand the highest possible picture quality from digital formats. Meanwhile, the dominance of home video and ever-present need for television broadcasting content, especially on specialty channels, has meant that films have proven a source of long-term revenue to a degree that the original artists and studio management before the rise of these media never imagined. Thus media companies have a strong financial incentive to carefully archive and preserve their complete library of films.
Video Aids to Film Preservation
The group Video Aids to Film Preservation (VAFP) became active on the Internet in 2005.
The VAFP site was funded as part of a 2005 Institute of Museum and Library Services (IMLS) grant to the Folkstreams project. The purpose of the site is to supplement already existing film preservation guides provided by the National Film Preservation Foundation with video demonstrations. The preservation guides provided by the origination, while thoroughly depicting accurate methods of preservation, are mostly text-based. The films and clips are copyrighted under the Creative Commons license, which allows anyone to use these clips with attribution—in this case, attribution to the VAFP site and to the author of the clip and his company.
Obstacles in restoration
Regardless of the age of the print itself, damage may occur if stored improperly. Damage to the film (caused by tears on the print, curling of the film base due to intense light exposure, temperature, humidity, etc.) all significantly raise the difficulty of the preservation process. Many films simply do not have enough information left on the film to piece together a new master, although careful digital restoration can produce stunning results by gathering bits and pieces of buildings from adjacent frames for restoration on a damaged frame, predicting entire frames based on the characters' movements in prior and subsequent frames, etc. As time goes on, this digital capability will only improve, but it will ultimately require sufficient information from the original film to make proper restorations and predictions.
Cost is another obstacle. In 2014, Martin Scorsese's non-profit The Film Foundation, dedicated to film presentation, estimated the average cost of photochemical restoration of a color feature with sound at $50,000 to $100,000 dollars, with digital 2K or 4K restoration at "several hundred thousand dollars." The degree of physical and chemical damage of film influences the incentive to preserve, i.e. as the business perspective states that once a film is no longer "commercially" viable, it stops generating profit and becomes a financial liability. While few films would not benefit from digital restoration, the high cost of restoring films digitally still prevents the method from being as broadly applied as it might be.
Demand for new media, digital cinema, and constantly-evolving consumer digital formats keeps evolving and shifting. Film restoration facilities must keep pace to maintain audience acceptance. Classic films today must be in near-mint condition if they are to be reshown or resold, with the demand for perfection only rising as theaters move from 2K to 4K projection and consumer media continues its shift from SD to HD to UltraHD and beyond.
Digital restoration steps
Once a film is inspected and cleaned it is transferred via telecine or a motion picture film scanner to a digital tape or disk, and the audio is synced to create a new master.
The main defects needing restoration:
- Scratches, tears/burned frames
- Color fade, color change
- Excessive film grain (a copy of an existing film has all of the film grain from the original as well as the film grain in the copy)
- Missing scenes and sound (censored or edited out for re-release)
- Shrinkage[nb 2]
Modern, digital film restoration takes the following steps:
- Expertly clean the film of dirt and dust.
- Repair all film tears with clear polyester tape or splicing cement.
- Scan each frame into a digital file.
- Restore the film frame by frame by comparing each frame to adjacent frames. This can be done somewhat by computer algorithms with human checking of the result.
- Fix frame alignment ("jitter" and "weave"), or the misalignment of adjacent film frames due to movement of film within the sprockets. This corrects the issue where the holes on each side of a frame are distorted over time. This causes frames to slightly be off center.
- Fix color and lighting changes. This corrects flickering and slight color changes from one frame to another due to aging of the film.
- Restore areas blocked by dirt and dust by using parts of images in other frames.
- Restore scratches by using parts of images in other frames.
- Enhance frames by reducing film grain noise. Film foreground/background detail about the same size as the film grain or smaller is blurred or lost in making the film. Comparing a frame with adjacent frames allows detail information to be reconstructed since a given small detail may be split between more film grains from one frame to another.
Photochemical restoration steps
Modern, photochemical restoration follows roughly the same path as digital:
- Extensive research is done to determine what version of the film can be restored from the existing material. Often, extensive efforts are taken to search out alternative material in film archives located around the world.
- A comprehensive restoration plan is mapped that allows preservationists to designate elements as "key" elements upon which to base the polarity map for the ensuing photochemical work. Since many alternative elements are actually salvaged from release prints and duplication masters (foreign and domestic). Care must be taken to plot the course at which negative, master positive and release print elements arrive back at a common polarity (i.e., negative or positive) for assembly and subsequent printing.
- Test prints are struck from existing elements to evaluate contrast, resolution, color (if color) and sound quality (if audio element exists).
- Elements are duplicated using the shortest possible duplication path to minimize analog duplication artifacts, such as the build-up of contrast, grain and loss of resolution.
- All sources are assembled into a single master restoration element (most often a duplicate negative).
- From this master restoration element, duplication masters, such as composite fine grain masters, are generated to be used to generate additional printing negatives from which actual release prints can be struck for festival screenings and DVD mastering.
The practice of film preservation is more craft than science. Until the early 1990s there were no dedicated academic programs in film preservation. Practitioners had often entered the field through related education (e.g. library or archival science), related technical experience (e.g. film lab work), or driven by sheer passion for working with film.
In the last two decades universities globally began offering graduate degrees in film preservation and film archiving, which are often taught conjointly (the latter focusing more on skills related to the description, cataloguing, indexing and broadly speaking management of film and media collections).
The recent years rapid incursion of digital technologies in the field has somewhat redefined the vocational scope of film preservation. In response, the majority of graduate programs in film preservation have begun offering courses on digital film preservation and digital film and media collection management.
Some established graduate programs in the field are:
- MA in Film Archiving, University of East Anglia
- Film Preservation Certificate, Selznick School of Film Preservation
- MA in Film and Media Preservation, Selznick School of Film Preservation offered jointly with University of Rochester
- MA in Moving Image Archiving and Preservation, New York University, Tisch School of the Arts
- MA in Heritage Studies: Preservation and Presentation of the Moving Image, University of Amsterdam
- Graduate Certificate in Audiovisual Archiving, Charles Sturt University, Australia
- Moving Image Archive Studies, UCLA
- MA in Film Preservation, Ryerson University, Canada offered since 2013 as specialization in the graduate program of Photographic Preservation and Collection Management
- Digital cinematography
- Digital intermediate
- Direct to Disk Recording
- Conservation and restoration of film
- Film recorder
- List of film formats
- Motion picture film scanner
- Orphan film
- Paper prints
- Post production
- Media Preservation Foundation
- Preservation (library and archival science)
- Preservation of magnetic audiotape
- List of national archives
- Academy Film Archive
- National Archives and Records Administration - USA
- Packard Humanities Institute
- George Eastman House
- Museum of the Moving Image (New York City)
- Separation masters
- 3D LUT
- Warner Bros. retained a pair of features from 1949 that they merely distributed, and all short subjects released on or after September 1, 1948, in addition to all cartoons released in August 1948.
- Linear and "across the web" (width), as well as localized puckering around large (1 to 2) perforation film cement splices, most common in silent and very early sound films. Highly shrunken film (1.5% or higher), must be copied on modified equipment or the film will most likely be damaged. In the case of flammable nitrate film, this could prove to be dangerous, as the film can jam in the duplicator and become idle. Some methods of duplication have illumination sources with enough heat to ignite the film if exposed to the light source for a long period of time.
- Yeck, Joanne L.; Tom McGreevey (1997). Our Movie Heritage. New Brunswick, NJ [u.a.]: Rutgers University Press. ISBN 0813524318.
- The Film Preservation Guide: The Basics for Archives, Libraries, and Museums. San Francisco: National Film Preservation Foundation. 2004. ISBN 0974709905.
- Kehr, Dave (14 October 2010). "Film Riches, Cleaned Up for Posterity". New York Times. Retrieved 23 July 2015.
It’s bad enough, to cite a common estimate, that 90 percent of all American silent films and 50 percent of American sound films made before 1950 appear to have vanished forever.
- Houston, P. (1994). Keepers of the frame: the film archives. British Film Institute.
- UNESCO, Recommendation for the Safeguarding and Preservation of Moving Images at UNESCO.org, 27 October 1980. Accessed 23 July 2015
- Hart, Martin (February 1993). "Robert A. Harris Presentation on Film Preservation". American WideScreen Museum.
- The Film Preservation Guide: The Basics for Archives, Libraries, and Museums. The National Film Preservation Foundation. 2004. p. 61. ISBN 0974709905.
- "twitchfilm.com. Jason Gorber's Cineruminations: 70mm, 4K, and THE MASTER's Split Personality Jason Gorber". Archived from the original on 2014-02-17. Retrieved 2014-04-12.
- postmagazine.com, Issue: November 1, 2012, Sound & Picture Restoration, By: Christine Bunish
- Image resolution
- Presto Centre Project web site
- Usai, Paolo Cherchi (2001) "The death of cinema: history, cultural memory and the digital dark age" British Film Institute
- Fossati, Giovanna (2009) "From grain to pixel: the archival life of film in transition." Amsterdam University Press
- Enticknap, Leo (2012). "Dossier: Materiality and the Archive." The Velvet Light Trap, (70), 63-64
- "MoMA.org | The Collection | Film and Media". The Museum of Modern Art. Archived from the original on February 7, 2006. Retrieved 23 June 2013.CS1 maint: unfit url (link)
- "Passion Cinéma" (PDF). Archived from the original (PDF) on 2006-06-27. Retrieved 2006-05-16.
- "Early Motion Pictures Free of Copyright Restrictions in the Library of Congress". Library of Congress. 31 August 2010. Retrieved 14 April 2011.
- Library of Congress-LOC Film preservation
- "Museum History · George Eastman House". Eastmanhouse.org. Archived from the original on October 6, 2008. Retrieved 14 April 2011.
- American Film Institute. "History of AFI". Afi.com. Retrieved 14 April 2011.
- Kula, S. (1979). Rescued from the Permafrost: The Dawson Collection of Motion Pictures. Archivaria, No. 8, Summer 1979.
- Shepard, R. (1990, Sept. 3). Expanding Archives: Library of Congress Is Not Just Books. The New York Times.
- The Library and Archives Canada Preservation Centre
- Morrison, Bill (2016). Dawson City: Frozen Time. KinoLorber. p. 1:53:45.
- About the BFI National Archive at British Film Institute official web site
- Johnston, Alva (24 October 1926). "Films Put on Ice for Fans yet Unborn". The New York Times.
Will Hays has sent a call to the motion-picture companies to search their vaults for ancient films of all kinds and for news reels of possible historic interest. The most important of these are to be treated by a process developed in the Eastman laboratories for making films immortal.
- Schickel, Richard; Perry, George (2008). You Must Remember This: The Warner Bros. Story. Philadelphia: Running Press. ISBN 978-0762434183.
- McCarthy, Todd (17 November 2013). "Hugo: Film Review". The Hollywood Reporter. Retrieved 23 June 2013.
- About the Foundation at storyofmovies.org
- "Video Aids to Film Preservation". Folkstreams. Retrieved 23 June 2013.
- film-foundation.org FAQ http://www.film-foundation.org/faq
- Lukow, Gregory. "Education Training and Careers in Moving Image Preservation". (AMIA, 2000)
- Audiovisual archives : a practical reader / edited and compiled by Helen P. Harrison for the General Information Programme and UNISIST. - Paris : UNESCO, 1997.
- Cave, D. (2008). "Born digital" – Raised an orphan?: Acquiring digital media through an analog paradigm. The Moving Image. 8(1), 1-13.
- Crofts, C (2008) Digital Decay. The Moving Image. 8 (2), xiii-35.
- Gracy, K. F. (2007). Film preservation: Competing definitions of value, use, and practice. Chicago: The Society of American Archivists.
- Karr, Lawrence. Edited by Barbara Cohen- Stratyner.: Film Preservation at Preserving America's Performing Arts. Papers from the conference on Preservation Management for Performing Arts Collection. April 28-May 1, 1982, Washington, D.C. Theater Library Association.
- Kula, Sam. Appraising Moving Images. Assessing the Archival and Monetary Value of Film and Video Records. Scarecrow Press, 2003.
- McGreevey, Tom: Our Movie Heritage. Rutgers University Press, 1997.
- Paul Read and Mark-Paul Meyer (Editors:): Restoration of motion picture film. Oxford, 2000. ISBN 0-7506-2793-X
- Slide, Anthony: Nitrate Won't Wait: A History of Film Preservation in the United States, McFarland and Company, 1992.
- Walsh, D. (2008). How to preserve your films forever. The Moving Image. 8(1), 38-41.
- National Film Preservation Board
- Historical Film & Video Preservation Society, Australia
- The Film Foundation (Martin Scorsese, President)
- National Film Preservation Foundation
- Video Aids to Film Preservation (VAFP)
- Public Moving Image Archives and Research Centers
- Association of Moving Image Archivists (AMIA)
- International Federation of Film Archives (FIAF)
- Conservation Online: Motion Picture Film Preservation
- Digital-Nitrate Prize for Film Preservation
- Collection of film restoration issues, collected by Joanneum Research
- The National Film and Sound Archive on Preservation
- The Journal of Film Preservation, published by FIAF
- The International Association of Sound and Audiovisual Archives
- Film Forever: The Home Film Preservation Guide
- Australian Network for Information on Cellulose Acetate