Photographs are complex chemical and physical items. Most photographs are comprised of an emulsion or image-bearing layer adhered to base or support material. The emulsion or image-bearing layer is usually chemically unstable and subject to damage from abrasion or chemicals (such as oil from fingers), while support materials can deteriorate, break, or tear. Digitally-printed photographs are comprised of a colorant (dye or pigment) applied to a simple substrate or image-bearing layer of a complex layered support material. Digitally-printed material can be extremely sensitive to abrasion, even from adjacent paper support materials, and are especially sensitive to moisture.
The fragility of some formats, such as cased photographs or glass plate negatives, often necessitates special housing. Consult with the Preservation Coordination Librarian about options. In these instances, consider the production of digital surrogate in order to minimize handling of the fragile photograph. For high value items, conservation treatment may also be an option.
Original photographic prints and digitally-printed photographs may be housed in Mylar sleeves to protect them from handling and environmental abrasion, as well as to provide support to unmounted photographic prints or to cracked paperboard mounts. Pigment inkjet prints should be housed in Mylar, or with Mylar interleaving, if they are likely to come in contact with coarse paper, including the versos of adjacent prints.
Large quantities of photographic prints in collections and series often necessitate economic strategies. The archivist should gauge anticipated use of the collection to decide whether large quantities of photographic prints warrant individual sleeves. In these cases, photographic prints may be housed in folders without sleeves. A note in the finding aid may alert the researcher that the photographic prints should be handled with care.
Item-level housing of photographic prints is carried out as follows:
- Select sleeves of a proper size for the individual photographic prints. Fold-lock Mylar sleeves should have the overlapping lock on the verso of the photographic print so that a line does not run across the image, which risks scratching the emulsion. If a Mylar sleeve is insufficient for support of particularly fragile items, consider adding another rigid support behind the photograph. Consult with the Preservation Coordination Librarian regarding other strategies.
- Per curatorial discretion, photographic prints of particular intrinsic or aesthetic value may be housed in mats cut to fit standard-size boxes for flat storage.
Oversize photographic prints should be housed flat in folders of a paperweight exceeding that of the base and/or mount of the photographic print. For extremely fragile large prints, consider matting for preservation.
Cased photographs (Daguerreotypes, Ambrotypes, and Tintypes) may be stored horizontally or vertically. Consult with the Preservation Coordination Librarian about any damaged cases, especially those with loose image packages. Daguerreotype and ambrotype plates without protective glass covers require immediate conservation attention to assure that no damage occurs to their fragile image-bearing surfaces. Tintype plates without protective glass necessitate housing in Mylar sleeves and should be stored in a manner that minimizes abrasion and chipping of the emulsion, as well as bending or breaking of the metal plate.
Due to their fragile nature, film negatives require attention and care, but do not necessarily require segregation from the original order within a collection. In most cases, properly housed photographic negatives may remain in a collection comprised of other material. Especially valuable or deteriorated color negatives may be routed to cold storage.
House loose film negatives in acid-free paper sleeves. Groups of 35 mm or 120 mm negative film may be housed in polyester binder sleeves (Printfiles). If a great deal of handling is expected, sleeve negatives in mylar before placing in paper sleeves, or as an alternative to them. Film negatives may be left in original housing if no deterioration is evident (consult the Preservation Coordination Librarian). If high use is anticipated, negatives for which no positive print is present should be sleeved in Mylar to protect them from inevitable handling as they are held up to the light.
Exceptions:
- Nitrate negatives are highly flammable and must be properly disposed. Consult the Preservation Coordination Librarian.
- Color film negatives, which may be housed in cold storage if particularly valuable or deteriorated.
Assume that any film negative created between 1889 and 1955, which does not have “safety film” printed along the edge, is cellulose nitrate film and route it for disposal. If there is no corresponding appropriate positive in the collection, a digital surrogate of the image should be created and added to the Digital Library.
Nitrate Film Policy:
Per the Yale Fire Marshall, and in compliance with the 2011 Edition of NFPA 40, Standard for the Storage and Handling of Cellulose Nitrate Film (2011 NFPA 40), the Beinecke Library does not store nitrate film or cut negatives on site, nor is it possible per the Yale Fire Marshall to store this material anywhere on campus. Likewise, it is not permitted to digitize nitrate film on campus; any creation of surrogates must be outsourced to a vendor, and transportation of the negatives to the vendor must be carried out in compliance with regulations for handling nitrate film. Therefore, as nitrate material is identified upon acquisition or during processing, the Library will discard the negatives according to established safety procedures, via the Yale Fire Marshall or via the digitization vendor.
Exceptions to the policy: some nitrate negatives belonging to the Beinecke prior to the implementation of this policy are [i.e. will be] in storage at the University of California, Los Angeles. This storage is limited and expensive; these holdings were selected by curators for permanent retention based on the potential research value of the original physical negatives. Future additions to the negatives in UCLA storage are not expected.
Nitrate Film Removal Procedures:
- Prepare and insert separation sheets into the original folders where the negatives were found, and then physically separate the negatives from the collection.
- Bring the negatives to the attention of the curator. The curator may wish to have the negatives, or some of the negatives, duplicated before destruction. The presence of positive prints (if known), the subject matter, the image quality, and the cost of transporting this material will factor in the curator’s decision.
- Properly document the destruction of the negatives:
- Record the destruction of the negatives as a deaccession within the accession record, and prepare a Deaccessioning Form to be signed by the curator. (The form and additional instructions can be found in the Accessioning documentation in Sharepoint.)
- Note the separation and destruction of the negatives in the finding aid at the collection level in the Processing Information field (EAD: <processinfo>), and at the file or item level if there will be digital object links for duplicated negatives.
- Route the negatives to the Preservation and Collection Management Unit (PCMU), with a copy of the Deaccessioning Form.
- For routine destruction without duplication, PCMU will take the negatives to the Yale Fire Marshall for destruction per Yale’s policy.
- If the curator has indicated that the negatives should be digitized, PCMU will arrange hazardous-material transport to the New England Document Conservation Center (NEDCC), which will digitize the negatives and then destroy them. The images will be added to the DL.
- Copies of all paperwork associated with the destruction of the negatives, such as the deaccessioning form and the additional form that accompanies the negatives to the Fire Marshall’s office, should be filed in the collection file.
Upon the separation or disposal of film negatives from a collection, complete a separation sheet (and, when appropriate, reference a surrogate image) for each file from which negatives were separated. The archivist may choose to print a physical surrogate from the Digital Library to place with the separation sheet.
In the case of deteriorating safety film negatives (e.g. shrinkage of the base layer, vinegar smell, warping, etc.), consult the Preservation Coordination Librarian and appropriate curator to determine whether a surrogate may be produced or conservation action may be taken.
Boxes of glass negatives should be segregated from the collection and stored on a shelf range that is in a fixed position rather than on movable shelving (consult Access Services for appropriate locations). Create a shelf dummy in the main box and folder sequence, pointing to this separate location. If there are only one or two glass negatives, they may remain within the main sequence in secure packages, as described below. This separation is for the preservation of the negatives and does not necessarily mean that they must be designated Restricted Fragile, although if positive prints are present in the collection, consider this option. If the negatives are particularly rare or important, consider designating them Restricted Fragile to protect them from risk of breakage in circulation; in this case obtain a reference surrogate for any image that does not have a corresponding positive print.
Place each glass negative in a four-fold wrapper or paper sleeve and label the wrappers with regular labels. Depending on the quantity of negatives involved, they may be boxed or sandwiched between pieces of mat board. Tie the box or sandwich with acid-free string and label it with the corresponding box and/or folder labels for the item(s) enclosed. In addition, include a label that identifies the contents as “FRAGILE – GLASS”
Broken glass plate negatives or lantern slides, or those items which show active emulsion deterioration or flaking, require consultation with the Preservation Coordination Librarian and the curator assess the options for conservation or special storage.
For the storage and handling of digital photograph files, consult the section on electronic files.
Most digitally-printed photographs found in collections are printouts of digital photograph files created on inkjet printers using dye or pigment colorants or a combination of the two (dye for cyan, magenta, and yellow; pigment for black). Dye inkjet prints can be highly unstable and their color tones and contrast levels may fade and diminish within months of creation. Pigment ink jet prints usually retain image continuity on par with traditional photographic prints. If a dye inkjet print is the only image available, consult the curator about creating a digital surrogate.