The division holds a variety of Special Collections consisting of groups of material that are related to each other and are housed together in the division. Some but not all of these collections are considered to be rare and are kept in the division's vault. Special requirements apply for their use and reproduction, including special handling procedures, additional registration forms, and a surcharge or “rare materials fee” for photoduplication orders. A considerable portion of this material has been cataloged and can be searched online. There are also many alternative and supplementary finding aids for special collections such as the preliminary, unpublished vault shelflist and unpublished inventories and indexes that are available for use in the division reading room.

Many rare materials have been photocopied at their original size. Black-and-white copies of these items can be purchased through written reference requests. Full color copies of items that have already been scanned and posted on the Web can be purchased directly from the Photoduplication Service. Researchers can also pay an additional fee to have a particular item scanned to produce a digital file or a copy of the original in a variety of sizes, if the material is no longer protected by copyright. Written permission of the copyright holder is required prior to reproducing items that are not in the public domain.