Film Preservation

Kristin MacDonough, a film student from NYU, during her internship with Laura Kissel, Archivist at the Byrd Polar Archive.

 

Kristin MacDonough is a Texas born University of Texas baccalaureate and Moving Image Archiving and Preservation graduate student at New York University interning for the summer of 2012 with The Ohio State University's Byrd Polar Research Center Archival Program. Her photos and blog entries about the process of the intial survay of these films are reproduced here.

 

The Archives was established in order to collect and preserve materials relevant to polar exploration and scientific discovery. Among these materials is a collection of films related to Admiral Richard E. Byrd for whom the polar research center and archival program is named after. Kristin worked under the Polar Curator, Laura Kissel, to begin evaluating the films in the collection in order to provide the archives with a better understanding of its holdings. Work included performing a collection assessment of approximately fifty boxes of film from both the Admiral Richard Byrd Archives and the Papers of Sir George Hubert Wilkins. It also involved furnishing the archive with materials for film inspection, performing film inspections and repairs, and providing instruction sessions with staff members for future inspections.

Blog Entry June 25, 2012

Film Decay and Decomposition: An introduction

 

Welcome to Decomposition week! Normally, I only post on Mondays, Wednesdays, and Fridays. However, I believe this material is rather important, so I will be posting information about the decay and decomposition of films everyday this week along with some applicable preservation steps.

 

During my first week here, I performed a collection assessment in order to understand the current condition of the items and what the next steps in preservation would be. I was in for quite a surprise. Let’s simply say the condition of the films was widely varied. Prior to being acquired by OSU, several of the films we stored in a variety of locations, many of which were not climate controlled. While it was crushing to find, I have to admit a somewhat perverse pleasure in uncovering these films.

 

Cellulose, of which both nitrate and acetate films are made, is a wood derivative. Therefore, all decomposition is inherently an inevitable organic reaction. Nitrate was used for 35mm films from the 1890s until about 1950, when the large companies, such as Kodak, phased into using only acetate for 35mm. Nitrate was quickly deemed unsafe when fires broke out in projection houses during the early 1900s. What makes it so hazardous is not only its flammability but that it is also nearly impossible to extinguish. In most cases, the firefighters could only wait till the fire burned itself out and then try to prevent it from spreading.

 

 

 

Nitrate Day                                                                                           Blog entry: June 26, 2012

 

Film is composed with two essential elements: the transparent plastic base and the emulsion. The plastic base is made from either cellulose nitrate, cellulose acetate, or polyester. The emulsion, which holds the image, is made with a thin layer of photosensitive materials and held together by a gelatin binding agent.

The first moving image films were created with cellulose nitrate, made by dissolving cellulose in nitric acid.  After some trial and error, celluloid sheets of the transparent film were developed by William Dickson of the Edison Company and patented in 1889 by Eastman Kodak.  Although knowledge of the compound’s inherent flammability was known before 1910, nitrate was used by the motion picture industry until 1950 due to its low production cost and high tensile strength.

 

Most decomposition occurs through hydrolosis, where chemical bonds break down with the introduction of water or humidity. In this case, the nitrate separates from the cellulose and mixes with water in the air to form nitric acid. This process creates acidic (nitric) fumes and in a closed container, like a film can, these fumes accelerate film degradation.

In the mid-1960’s, FIAF (International Federation of Film Archives) identified five stages of nitrate decay:

 

  • The silver image begins to fade and the emulsion turns a brownish color.

  • The emulsion becomes sticky and faint noxious odors become apparent.

  • The emulsions softens and begins to bubble, “honey” effect. Odors become stronger.

  • Film congeals into a solid mass.

  • Film disintegrates into a brownish, rusty powder. At this stage, film has a low ignition temperature. (and whew!! the smell!!)

 

With the above in mind, imagine my reaction to uncover the below. For example, my automatic reaction was akin to opening a can of live bugs. Big, ugly bugs. The finding aid for this material simply listed these as “damaged films”. If you are working with film and come across items in this condition, don’t over-fret. (… unless you’re working in a room where the temperature is over 100° F or working next to an open flame… which I hope you would not do under any circumstances.) Still, decomposed nitrate is a hazardous material and should be handled and disposed of properly. In this case, we placed the films back in cool storage and I contacted to the Hazardous Waste department in the Office of Environmental Health and Safety at OSU to safely remove the films.

(Just a quick reminder. These films were stored in various, non-climate controlled conditions for several years prior to OSU taking them in. The archival departments at OSU use excellent storage for their materials.

Acetate Day                                                                                            Entry June 27, 2012

 

Acetate film was created around 1910 as a safer, less-flammable, alternative to nitrate. In a similar fashion to nitrate, it is created by dissolving  cellulose in an acid but an acetic rather than nitric acid. The first iterations of the acetate base were very fragile and tended to decompose quickly (cellulose diacetate). This characteristic kept nitrate as the primary film base for 35mm. During the 1930s, manufacturers developed stronger compositions of acetate (cellulose acetate propionate and cellulose acetate butyrate) until finally settling on cellulose triacetate in the 1940s, the strongest of the acetate family. 16mm and 8mm films, being designed for the home and amateur filmmakers, were created only on acetate “safety film” bases.

 

However, each family member still has something in common: the process of acetate decomposition. Like nitric acid, acetic acid is also affected by the process of hydrolysis (chemical bonds breaking down with the introduction of water or humidity). Acetic acid is chemically identical to vinegar, so when the acid begins to separate from the cellulose, it emits vinegar smell, leading archivists and preservationists to refer to the process as “vinegar syndrome”. Film preservationists have also identified this process in a few general steps:

 

  • The film starts to smell like vinegar and the base begins to soften.

  • The film begins to shrink, and early stages of warping occur.

  • The film starts to become stiff as the acetic acid continues moving out of the base. Warping such as buckling or edge wave occurs.

  • The emulsion and base shrink at different rates, causing them to separate and emulsion may crack and flake off. Warped film continues curling and spoking.

  • White powder (not mold) appears along the surface and edges of the film. Roll of film can solidify into a solid mass.

 

In the early stages, the scent of mothballs can also occur in early cellulose diacetate films, when naphthalene, a chemical within the base is separated due to the acetic acid. The buildup of acetic acid accelerates the process of decomposition making vinegar syndrome contagious if infected films are stored to closely with other films.

(Reminder: Not all films in the Byrd film collection are in this condition. This week represents only a fraction of the total films, most of which are in good and preservable condition.)

(side note: I’m thinking of having a “penguin day” next week…)

 

Other issues in film decay                                        Blog Entry June 28, 2012

 

Besides hydrolysis affecting the base, water can damage film in other ways.  As described before, to create the moving image, two important elements are necessary: the base (nitrate, acetate, or polyester) and the emulsion.  If the film is subjected to immersion in water, the emulsion will soften and begin to separate from the base. Also, in high heat and humidity, mold, mildew, and fungus can grow and be detrimental to film. Starting from the edge of the film and working its way in, the biological agent will eat away at the emulsion and once the image is gone, it is gone forever.

Early signs of mold are white blotches along the side of the reel. If signs of mold are caught early, the agents can be removed with a thorough cleaning and prevented with proper storage.

 

(Reminder: Not all films in the Byrd collection are in this condition. Prior to acquisition by the Polar Archives, these films were stored in a variety of non-climate controlled environments.  Decomp Week represents only a small fraction of what was uncovered during the collection assessment. Most films are in good and preservable condition.)

 

 

 

 

 

I’m pretty sure this is a person eaten away by mold…

As fungus grows, it develops a lace pattern along the side of the reel and usually hints at the extent of damage caused.

This blog was re-printed with the generous permission of Kristin MacDonough. You can see her original blog about the film preservation process along with photos and references here.

Acetate was introduced around 1910 as a safe substitute for nitrate. All films produced on acetate were subsequently labeled “Safety Film” along the edge. (Since nitrate was still in production, companies began labeling it “Nitrate Film”.) There are several different chemical compositions of cellulose acetate but I will discuss those later. 16mm  and 8mm formats, released in 1923 and 1932 respectively, were only produced with acetate, never nitrate.

 

For some enticement, here’s a 35mm “gold star”…

The footage from BYRD 1933 is found footage from 28 reels of film (only 10 survived ultimately) that were logged and preserved at the Byrd Polar Archive and then were conserved and transferred to digital mediums through a generous grant from the National Film Preservation Foundation in 2013-2014. The information below is a re-print of the initial archive activities at the earliest stages of preservation in 2012.

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