Assignment #4: Mass Deacidification at Northwestern Univeristy

The Preservation Department website for Northwestern University Library indicates that their mass deacidification program falls under the purview of the Materials Processing unit, along with library binding and brittle book reformatting. The site claims that over 60% of the paper-based collections at Northwestern fall into the "acidic, but not yet brittle" category, making them suitable for deacidification. They provide a nice series of photographs outlining their deacidification process, which is the Bookkeeper treatment from Preservation Technologies, LP.

According to the website, Northwestern's deacidification efforts are focused on the Music and Africana collections and in FY 2005 they sent 6,130 items for treatment. The department's annual report for FY 2007-08 reveals that, in addition to these 2 collections, materials from the Transportation Library were deacidified. The report also indicates a desire to apply the Bookkeeper treatment to larger archival collections, which the library has plans for in 2008-09. 6,656 items were sent for deacidification in 2007-08. The conservation unit is responsible for quality control on these items.

This information raised a couple of questions for me:

• When & how did they arrive at the 60% figure - a preservation survey, perhaps? More specifically, I would be interested to know the qualities & values of the chosen collections that make them top priorities.
  

• How is quality control conducted on the deacidified objects? The library is clearly happy with the results since they are continuing to expand their deacidification program, but I wonder what exactly is being checked when the objects are returned.