Our Policies
Our most up to date procedures and standards are shared at our Digital Collections Documentation site.
Scanning and Preservation Procedures
Scans are performed and saved as non-compressed Tiffs. Complete copies of our scans and metadata are stored in a geo-replicated dark archive drive, as well as external hard drive backups. Variable scanning resolutions are described below.
Manuscripts/Documents:
- 8 X 11 paper - 400 dpi
- Pieces of paper smaller than 5 x 7 are scanned at 600 dpi
Photographs, Slides & Negatives:
- All photographs are scanned in color
- 8 x 10 and up scan at 400-600 dpi
- Images between 5 x 7 to 8 x 10 scan at 400-600 dpi
- 5 x 7 down to 3 x 5 scan at 600 dpi
- Smaller than 3 x 5 scan at 1200 dpi
- At least 6,000 pixels on the long edge
3D objects:
- All 3D objects are photographed at 400-600 dpi
- When possible various sides of the object are photographed
- Photographs capture significant details on the object that add to its value
Feed Scanner:
- Larger documents are scanned using our feed scanner
- Pages are scanned anywhere from 400 - 600 dpi
Metadata Guidelines
Metadata is the information we create to describe each item in our collections. We follow standards to make sure that our descriptions are consistent across items and ensure that users can find what they’re searching for.
We follow the Dublin Core Metadata Practices, which provide us a standard for how we format our metadata and make the information readable for a large audience and aggregators. All collections start from a base template created in collaboration with Special Collections and Archives, but may include additional fields following the needs of the material.
References
The below sources guide our metadata, scanning, and preservation practices:
Authority Sites:
- LCSH (Library of Congress Subject Headings)
- AAT (Getty’s Art and Architecture Thesaurus)
- LCTGM (Library of Congress Thesaurus for Graphic Materials)
- USGS (U.S. Geological Survey)