Volume 23, Number 2
1999

Preservation Research at the Library of Congress

At the 1998 American Library Association, research projects underway in LC's Preservation Research and Testing Division were reported in the Preservation Administrators Discussion Group (PADG) meeting. They included investigations of moving image and audio preservation, risk assessment studies for a magnetic tape collection and motion picture collections, digital technology applications, book and paper preservation, pressure-sensitive labels, PVA adhesives, paper aging, and LC's part in the ASTM/ISR project on accelerated and natural aging.

The work on moving image and audio materials involved

accelerated aging of magnetic tape,

cleaning of acetate disks, and

risk assessment studies for motion pictures and magnetic tapes.

The risk assessment study for the magnetic tape collection found that 90% of in-house productions were in good condition, and that tapes stored in the Madison Building had a life expectancy of 40 years. Almost all tapes received from other sources had "sticky shed" problems, some of them advanced. (However, Dr. Chandru Shahani, author of the report, said putting the tape in an oven at 60°C or so appears to reverse the condition.)

The risk assessment study for the motion picture collections found that 55% had no vinegar syndrome deterioration; less than 5% were in an advanced state of vinegar syndrome deterioration. Forty percent of color film has faded significantly. Film in the Madison Building has a life expectancy of 40 years, but film in LC's Landover cold vaults has a life expectancy of 900 years.