{"id":2385,"date":"2019-07-09T15:07:32","date_gmt":"2019-07-09T15:07:32","guid":{"rendered":"https:\/\/libapps.libraries.uc.edu\/thepreservationlab\/?p=2385"},"modified":"2019-07-09T15:07:32","modified_gmt":"2019-07-09T15:07:32","slug":"the-protective-power-of-interleaving","status":"publish","type":"post","link":"https:\/\/libapps.libraries.uc.edu\/thepreservationlab\/2019\/07\/the-protective-power-of-interleaving","title":{"rendered":"The Protective Power of Interleaving"},"content":{"rendered":"

You might know the importance of a protective enclosure, but how often to you consider the quality of storage materials?\u00a0 In fact, the composition of storage materials plays a significant role in the preservation of archival collections.\u00a0 But how?
\nSince storage plays a passive role, the positive and negative interactions of storage materials may not be readily apparent.\u00a0 Chemical reactions that occur between library and storage materials are often a slow process, spanning over a number of months or years before a visual change occurs.\u00a0 Without the gratification of seeing immediate effects, many may not realize how some storage materials can be problematic, let alone the ramifications for using non-archival materials.
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\nTo illustrate some of the effects, I thought I\u2019d share a vivid example of protection from acidic materials during storage. The following photograph shows the positive effects of archival buffering paper (also known as interleaving), as well as the danger of using non-archival boards and tapes \u2013 even when they are not in direct contact with the object!
\nThe protected object is a 17th<\/sup> century printed broadside.\u00a0 It\u2019s a single sheet of paper with printed black text on the front.\u00a0 The broadside was stored for many years in a green cloth-covered portfolio.
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Within the portfolio, the broadside was secured beneath with folded sheets of plastic film with a blank sheet of paper.\u00a0 You can see the plastic film is attached to the portfolio around the edges with green tape.<\/p><\/div>
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This image shows the front of the blank sheet of paper stored side the plastic film, below the broadside. The plastic has yellowed overtime.<\/p><\/div>
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Here, the blank sheet is removed, revealing yellowish-brown discoloration around the top and right edge. This discoloration aligns perfectly with the green tape that is adhered on top of the plastic \u2013located on the top and right side of the plastic.<\/p><\/div>
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When you flip the paper over, the back of the blank sheet shows even more discoloration. In fact, the discoloration is a mirror image of the materials below the plastic! This has occurred because the plastic is \u201cbreathable.\u201d The materials below are all acidic, except for the white fragments of paper, which protected a portion of the paper from turning brown.<\/p><\/div>
\nThe interleaving paper served two purposes here:<\/p>\n

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  1. Acts as a support for the broadside when handled.<\/li>\n
  2. The interleaving served as a sacrificial barrier that absorbed the bulk of acidic off-gassing from the non-archival paper and tape.<\/li>\n<\/ol>\n

    In summary, this enclosure is an excellent example of how different materials can interact with one another in nuanced ways, and how plastic is actually a permeable barrier to gasses overtime!
    \nGeneral storage tips:<\/p>\n