Getting It On Record: Stabilization, Enhanced Imaging, and Documentation of Archival Instantaneous Audio Discs

David M. Walker
The Electronic Media Review, Volume Five: 2017-2018

ABSTRACT

In 2017, audio media conservators at the Center for Folklife and Cultural Heritage, Smithsonian Institution, conducted conservation documentation and rehousing for over 4,100 unique audio discs. The documentation process involved assessing, stabilizing, and identifying treatment priorities for fragile lacquer and aluminum discs, many of which comprise one of the largest collections of early 20th century ethnographic recordings. Nearly 70 years after their creation, many of the recordings display a range of condition issues not uncommon to the media format, including physical damage, delamination, plasticizer exudation, warping, crazing, and evidence of biological growth. As part of this project, high-resolution digital images were created using efficient workflows to generate enhanced views of each disc to highlight material condition and to document unique surface features, such as etched-in song titles, performer names, matrix numbers, and intentional groove destruction. Their documentation provided archivists with a framework for establishing holistic treatment plans and highlighting preservation digitization priorities. This case study describes the procedures developed over the course of the project and assesses the immediate and long-term benefits of conservation documentation outside of direct treatment. The paper will be of most interest to time-based media conservators, collections managers, preservation specialists, and archivists working with legacy recorded sound media.

INTRODUCTION

From October 2017 to March 2018, audio media conservation specialists at the Center for Folklife and Cultural Heritage, Smithsonian Institution, completed a conservation documentation and rehousing project for over 4,100 instantaneous audio discs and unique test pressings. The primary goal of the collections care project was to assess, stabilize, and identify treatment priorities for each disc. Their documentation provided archivists with a framework for establishing holistic treatment plans and preservation digitization priorities.

As part of this project, high-resolution digital images were created during the inspection process for each disc using efficient workflows to generate enhanced views. The images produced highlight the range of condition issues that this format experiences and document the unique surface features, such as etched-in song titles, performer names, matrix numbers, and intentional groove destruction. Once completed, an additional eight-week digital asset management project was carried out to properly steward over 12,000 digital images of the recordings and their associated papers. The projects were supported by the Smithsonian National Collections Program through the Collections Care and Preservation Fund and by the Smithsonian Collections Information Management Committee through the Collections Information System and Information Resource Management Fund.

PROJECT BACKGROUND

In 2015, the Moses and Frances Asch Collection—held by the Center for Folklife and Cultural Heritage—was recognized as a veritable “encyclopedia of sound” by the United Nations Educational, Scientific, and Cultural Organization (UNESCO) and added to the organization’s Memory of the World Register (UNESCO 1). Of the many thousands of papers and audio recordings in this collection are unique examples of early and mid-20th century studio performances, radio transcriptions, and field recordings by famous and lesser-known artists, writers, documentarians, ethnographers, and grass roots musicians from around the world. This collection represents the largest majority of instantaneous discs held by the Center for Folklife and Cultural Heritage and the earliest recordings are in the form of highly fragile lacquer or aluminum discs. To better preserve these significant but volatile recordings, archive staff had to first gather item-level condition information to establish future preservation goals.

Format Characteristics and Ideal Storage Conditions

While format migration from physical carriers to digital files is the accepted long-term preservation strategy for archival audiovisual content, stabilizing and documenting the conditions of the physical carrier is the cornerstone of any sustainable digitization plan. Lacquer and aluminum discs present unique collections care challenges for museums, archives, and libraries, typically requiring stabilization and treatment before preservation digitization can be attempted. These materials can be easily damaged through improper storage and handling and they can also experience accelerated deterioration owing to moderate fluctuations in temperature and relative humidity. The International Association for Sound and Audiovisual Archives recommends storing instantaneous discs in cool, dry environments with around 40% to 50% relative humidity (RH) at a temperature around 68°F, with a narrow variability of ± 3% RH, ± 2°F (Schüller 2014, 34) to slow the rate of deterioration. Storage outside of the recommended range can lead to a number of permanent material changes, including plasticizer exudation, shrinkage, crazing, cracking, biological growth, and delamination, all of which considerably lengthen the amount of time required to perform preservation digitization or can hinder it completely. For the discs in the Moses and Frances Asch Collection, the quickest and most effective way to improve the physical and environmental conditions around the materials and slow their rate of decay was to replace their housing and relocate them to a more appropriate section of the archival repository. Prior to the rehousing project, the discs were packed tightly in vertical mail slot–style shelving units that were insufficient for withstanding the combined weight of the materials (fig. 1). It was decided that the shelves, too, needed to be replaced with sturdy open shelving to allow archivists to select more appropriate housing options aligning with preservation and access needs.

METHODOLOGY AND WORKFLOW

Replacing Housing

For this project, it was necessary to replace all old sleeves with acid-free buffered sleeves that could be safely inserted into boxes of the correct dimension. Storing discs vertically in reinforced acid-free boxes designed to accommodate 10-inch, 12-inch, and 16-inch discs allowed them to maintain a vertical orientation without adding extra pressure on either side (fig. 2). Boxes provide an environmental barrier that helps to stabilize the micro-climate around the discs and adds an extra layer of protection against physical damage or moisture. Using boxes also increased the intellectual control and accessibility of the materials, as they can be clearly labeled with the range of items inside. Each box was filled with no more than 30 discs each to avoid overcrowding or adding excess weight. For severely delaminated, cracked, or oversized discs, flat boxes were used as temporary storage until custom housing can be created for each disc in future projects.

Figure 2. View of completed rehousing, including reinforced disc boxes, archival sleeves, and spacers

Condition Documentation

Several of the discs were already known to have been damaged before rehousing began, but there was very little specific condition information available except for the occasional handwritten note on the original sleeve. It made sense, then, to gather critical material and condition information for each disc during the rehousing process. The key fields documented included base material type; dimension; and evidence of damage, such as delamination, crazing, biological growth, intentional groove destruction, and other common issues with the format. At the beginning of the project, the condition-reporting process for these discs took the form of item-level assessment and logging into an Excel spreadsheet. However, the project took a significant turn when the media conservators realized that the work could be improved with the addition of digital photography. Not only did photography allow for easier measurement and enhanced viewing of surface features but it also enabled non-condition information to be documented, such as descriptions contained on the sleeves and labels or impressions in the discs indicating date or matrix number. With some consultation with photography professionals at other Smithsonian units and initial experimentation, a system was developed that allowed media conservators to generate high-resolution digital surrogates that reduce the need to handle the materials in the future to verify visible technical, condition, or descriptive information.

Digital Photography

Using The AIC Guide to DIGITAL Photography and Conservation Documentation, second edition (Warda et al. 2011) as the foundation for the photographic stage of this project, the audio media conservation specialists designed a setup that made the condition-reporting process more efficient and reliable. The most common way to photograph fragile two-dimensional objects is from an overhead position using some combination of a camera mounted on a copy stand surrounded by strategically placed lighting. For the highly reflective flat discs with subtle surface details, the setup that yielded the most consistent and accurate results consisted of a DSLR camera back with interchangeable 50-mm and 100-mm fixed focal length art lenses, an adjustable copy stand, and four continuous LED light panels positioned at each corner of the stand.

There were some initial challenges, however, with arranging the equipment to produce images that were compliant with the Federal Agencies Digital Guidelines Initiative four-star rating system. In order to achieve a four-star image, the shooting platform needed to have evenly diffused lighting to illuminate the surface details of the dark reflective discs. Initial tests with two lights yielded images with areas of high contrast that failed image quality assessment tests. By placing four diffused continuous lights equidistant from the center of the shooting platform, the surface features and grooves emerged and the camera rendered accurate representations of the discs under normal light. Also problematic were reflections of the overhead photography equipment on the glossy surfaces. In the end, this issue was remediated by placing a large black foam board at the end of the lens to serve as a neutral backdrop. Consultations early on with staff photographers at the National Museum of African American History and Culture and the Smithsonian Institution Archives were essential in resolving some of these photography issues.

Here are some of the specific technical methodologies employed during the photographic stage:

Device-level image targets were used and verified at the beginning of each photo session to confirm accurate equipment alignment and calibration.
Image-level targets were included in each photo to ensure color and spatial accuracy in each shot.
A laser parallel alignment tool was used weekly to verify lens alignment.
A neutral gray board was chosen as the background for each disc, as it provided a soft shooting surface and was easily cleaned before each session.
Discs were placed on the shooting platform and minimally adjusted to align the center hole with a fixed point on the board.
The Canon EOS photo utility was used to control camera values and shoot remotely to minimize vibrations caused by manual operation of the camera (fig. 3).
Discs were shot in ranges according to size to reduce the amount of height adjustment needed to get the best quality images.
For each disc, at least three images were produced: one of the old sleeve and one of each side.
Additional shots were taken for severely deteriorated items, notable features, and associated papers or documentation.

Throughout the condition-reporting process, all types of deterioration were observed: from structural issues such as shrinkage, crazing, and loose cores, to exudation and discoloration, to delamination and physical damage. The majority of the discs were noted to be relatively stable and housed normally, but a small portion of around 150 had to be segregated from the bulk of the collection for custom housing. Figures 4 to 11 showcase some notable examples of the main issues observed.

Figure 3. Overview of remote shooting software application and camera settings

Figure 4. Normal lacquer disc with minor delamination

Figure 5. Lacquer disc exhibiting discoloration

*Figure 6. Close up view of crazing on lacquer disc*

*Figure 7. Close up view of moderate plasticizer exudation on lacquer disc*

*Figure 8. Close up view of glass-based lacquer disc with loose core*

*Figure 9. Close up view of severe plasticizer exudation on lacquer disc*

*Figure 10. Lacquer disc exhibiting delamination*

*Figure 11. Broken glass–based lacquer disc*

Digital Asset Management

After the photography and condition-reporting stages were complete, it was necessary to manage the many thousands of files generated throughout the course of this collections care project. A digital asset management technician was hired to transform camera raw images into digital negatives (DNG) embedded with IPTC metadata and to produce image-adjusted TIF derivatives. Over the course of eight weeks, the technician inspected each file—performing quality control assessments; recommending re-photography as needed; and conducting general image file maintenance, such as converting and rotating the images. A second set of derivative images was created from the raw originals by shifting the black levels up to bring out subtle details etched into the disc surface without introducing additional image noise or distortion. A bulk metadata spreadsheet was then created by collating the administrative and descriptive information from other sources and combining it with the condition and material information captured in the reporting stage. Using Adobe Bridge CC and IPTC plugins, metadata was imported in batches and then the images were ingested by the Smithsonian Institution’s Digital Asset Management System. Embedding condition notes into the image metadata proved to be a reliable way to ensure that the item-level information captured during the condition-reporting stage persisted with each individual file. Since the Digital Asset Management System can read IPTC metadata files, all notes are easily searchable within the network.

The last step in the digital asset management project was to begin linking the final images with the finding aid records for their publication on the Smithsonian Online Virtual Archive. As noted previously, access to the physical discs is limited to prevent further damage to the discs. The digital surrogates, when presented online alongside the finding aid, enable researchers to access information about each instantaneous disc held by the Center for Folklife and Cultural Heritage (fig. 12).

Figure 12. Overview of enhanced views published on Smithsonian Online Virtual Archive

CONCLUSION AND FUTURE WORK

From the data gathered in this condition-reporting project, new preservation plans have been established to improve the condition of these historic recordings, including disc cleaning, digitization of stable discs using in-house means, custom rehousing of the segregated broken discs, and eventual digitization of the broken discs using emerging noncontact methods of transfer. The digital images of the recordings, however, will continue to serve as an archival record for staff and researchers alike and will augment the research experience when displayed alongside the digitized recorded content.

ACKNOWLEDGMENTS

The author would like to thank the following people and organizations for their support of this project: William G. Tompkins, Director, National Collections Program, Washington, DC; Ken Rahaim, Senior Mass Digitization Program Officer, Smithsonian Digitization Program Office, Washington, DC; Nora Lockshin, Senior Conservator, Smithsonian Institution Archives, Washington, DC; Catharine Hawks, Conservation Specialist, Smithsonian National Museum of Natural History, Washington, DC; Mary Coughlin, Assistant Professor of Museum Studies, Corcoran School of the Arts & Design, Washington, DC; Stephanie Smith, Archives Director, Ralph Rinzler Folklife Archives & Collections, Center for Folklife and Cultural Heritage, Smithsonian Institution, Washington, DC; Rori Smith and Crystal Rie, Archives Technicians, Ralph Rinzler Folklife Archives & Collections, Center for Folklife and Cultural Heritage, Smithsonian Institution, Washington, DC.

REFERENCES

Schüller, D., A. Häfner, and G. Boston. 2014. “Handling and storage of audio and video carriers: technical committee standards, recommended practices, and strategies.” London: International Association of Sound and Audiovisual Archives.

United Nations Educational, Scientific and Cultural Organization. 2015. “Moses and Frances Asch Collection. Center for Folklife and Cultural Heritage, Smithsonian Institution.” http://www.unesco.org/new/en/communication-and-information/memory-of-the-world/register/full-list-of-registered-heritage/registered-heritage-page-5/moses-and-frances-asch-collection-center-for-folklife-and-cultural-heritage-smithsonian-institution/ (accessed 02/01/18).

Warda, J., F. Frey, D. Heller, D. Kushel, T. Vitale, and G. Weaver. 2011. AIC guide to digital photography and conservation documentation.3rd ed. Washington, DC: American Institute for Conservation of Historic and Artistic Works.

SOURCES OF MATERIALS

Rehousing Supplies
HOLLINGER METAL EDGE
PRS-7
PRS-10/PD-10
PRS-12/PD-12
PRS-16/PD-16
https://www.hollingermetaledge.com

Photography Equipment
Canon 5DSR
Genaray SpectroLED Essential 500 Daylight LED Light (4)
Image Science Associates Device Level and Object Level targets
Kaiser Copy Stand RSX with RTX Arm
Sigma 50mm f/1.4 DG HSM Art Lens for Canon EF
Sigma 105mm f/2.8 EX DG OS HSM Macro Lens for Canon EOS Cameras
Versalab Parallel Alignment Gauge
B&H Foto & Electronics Corp.
420 9th Ave.
New York, NY 10001
800-606-6969
www.bhphotovideo.com

Software and Utilities
ADOBE SYSTEMS
Adobe Bridge CC 2018
Adobe Camera Raw 10
Adobe Photoshop CC 2018

CANON USA
Canon EOS Utility 3.8.20 for Windows

PICTURAE
Delt.ae image calibration utility

OPEN SOURCE
IPTC Cultural Heritage Metadata Panel for Adobe Bridge

David M. Walker
Audio Media Conservator
Center for Folklife and Cultural Heritage, Smithsonian Institution
WalkerDM@si.edu