AzAA Blog Post September 2021

September 2021

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This month we feature a write up from Trent Purdy, Assistant Librarian and Archivist with the Special Collections department at The University of Arizona Library and former Board member of Arizona Archives Alliance and Amanda Howard, Library Information Associate with the Special Collections department at The University of Arizona Library regarding their work digitizing an amazing audio visual collection at their institution and the attention to detail that is needed to process audio visual recordings in archives. We thank Trent and Amanda for this amazing look into this project and the work they do at the Special Collections department at The University of Arizona Library.  

In March 2020, the University of Arizona Libraries Special Collections was awarded a prestigious Recordings at Risk grant from the Council on Library and Information Resources (CLIR) to digitize and preserve ninety 16mm and 35mm motion picture films from the collection of dendrochronologist and founder of the Laboratory of Tree-Ring Research (LTRR), A.E. Douglass. Multimedia Archivist Trent Purdy and Archival Assistant Amanda Howard are Co-PIs on the grant.

Some of these films are nearly one hundred years old–spanning a thirty year period in Douglass’s academic career–from the mid-1920s to the mid-1950s. Before the films came to live in Special Collections in the early 1990s, they were stored in the Laboratory of Tree-Ring Research, which was located in the west side of the Arizona Stadium before it moved to the Bryant Bannister Tree-Ring Building.

Storage in Special Collections allowed the films to be held in a climate-controlled area, but photos below give a sense of the conditions: a hodgepodge of loose film secured with string or in original box mailers from the 1920s and ’30s, film in rusty cans and on rusty reels. This is not unusual for audio-visual collections in archives, which require special enclosures and storage precautions as we’ll see later, as well as specialized archival training in the care of AV. Most archives simply do not have the capacity for these expensive resources.

Prior to applying for the CLIR grant, an extensive process of inspection was needed to assess condition and level of deterioration of each film. Beginning in the spring of 2018, Amanda used some tools of the trade–a rewind bench, guillotine splicer, and A-D strips—to perform this delicate work.

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[Lessons in what not to do in caring for films: store loose in rusty canisters, film boxes, and envelopes, secure with rubber bands and string.]

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[Tools of the trade for film inspection: rewind bench, split reels, guillotine splicer, archival film core, gaffer’s tape for sealing canisters, loupe, gloves, pen for labeling leader, archival canisters and film leader.]

A-D strips measure the level of degradation of cellulose acetate film based on acidic vapor produced by the item. The breaking down of acetate film produces a vinegar-like odor, giving it the name “vinegar syndrome.” 

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[A-D strips are sealed inside archival film canisters for 24 hours to sample the amount of acetic acid being off-gassed by the film. This 16mm film has an A-D strip reading of about .25]

A-D strips change color–a range of blue to yellow–in the presence of acetic acid, and are read on a scale from 0-3; the greater the acidic reading based on the color of the strip, the greater the deterioration of the film. A process of rapid deterioration known as autocatalytic decay accelerates exponentially at a reading of 1.5 and above. Of the ninety films in the Douglass papers, around thirty-five registered an A-D strip reading of .50 to 2.50. The remaining fifty plus films in the collection registered a .25 A-D strip reading or below. The deterioration of films reading at .50 or above can be slowed by placing them in frozen storage. Special Collections has its own frost-free freezer for just this purpose.

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[Lime green strip (A-D 2.0) = “Bad news. Freeze me quick!” This film actually has a polyester base, but absorbed acetic acid from its nearby acetate friends. Whether acetate or polyester, freezing motion picture film will slow deterioration and extend life.]

Prior to shipping the films to the vendor in Pennsylvania for digitization, we created descriptive metadata in the form of Excel spreadsheets. The first spreadsheet contained descriptive metadata using a combination of MODS and PBCore elements.

MODS (Metadata Object Descriptor) is a metadata standard developed by the Library of Congress for library assets of all kinds, while PBCore is a metadata standard developed by the Corporation for Public Broadcasting to be used specifically for audiovisual content. Each of these allows for uniform, consistent descriptors across items, e.g. title, genre, language, and date. Descriptive metadata is generated to improve researcher discoverability and accessibility of content as well as preservation of both the physical films and corresponding digital surrogates. The second spreadsheet contained descriptive metadata which is embedded into the preservation (.mkv) and access files (.mp4). Embedded metadata ensures long-term preservation of digital files.

Once the vendor completed digitization of the films, we received a hard drive containing project deliverables which included XML metadata records and master and access video files of the original motion picture films. We then set out performing quality control (QC) on the files. This is a time-consuming process that requires extreme attention to detail, but is essential to long term preservation as well as researcher discovery of these one-of-a-kind materials. This process includes, amongst other things, ensuring that all project materials are digitized and checking metadata records for accuracy. We also watch portions of the motion picture master and access files.

Once the files passed the QC process, we created a digital collection on our Aviary site and uploaded the .mp4 access files and related descriptive metadata.  Amanda then utilized extant shot lists generated by LTRR faculty in the 1990s to create robust indexes, which in addition to descriptive metadata, greatly enhances researchers’ discovery of content.

As archivists we are very grateful to CLIR and other like-minded nonprofit funding organizations that understand the work we as archival professionals do to ensure the preservation of and access to unique primary source materials. It’s been humbling to be part of the stewardship chain of these wonderfully fascinating films, a chain that started with Dr. Douglass when he loaded film into his camera at the various sites depicted in the films and began shooting. Professionally, through this project we gained invaluable experience managing a grant project which laid the foundation for pursuing future grants to preserve other AV treasures in Special Collections.

Published by Arizona Archives Alliance

The Arizona Archives Alliance is a nonprofit organization that advocates for Arizona's historical archives and their users, provides training to archivists and archive volunteers, and promotes the use of Arizona’s historical archives.

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