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 10_pixel_square.gif Deciding on a course of action

Once a collection's potential problems have been identified, you'll need to decide on the best course of action. In order to do so, consider a range of basic factors. How valuable is the collection, both monetarily and intrinsically? How many laminated objects are involved — a dozen or thousands? How does the laminated material fit in your institution's priorities? How are the objects currently housed, protected, stored, and handled? Is it important that the objects be stable enough to travel, or to be exhibited?

Realize that most archives will simply have to live with their laminated materials. Although conservators can remove the laminate, delamination is a major investment with potential risks to the objects; before considering delamination, there are several basic steps that you should take to limit damage.

 10_pixel_square.gif Practical advice for laminated objects

Maintain an appropriate storage environment. The first priority is to stabilize the environment in which the objects are stored. As with most paper-based collections, laminated objects are best stored at a constant relative humidity (around 50%) and temperature (70° F) (see Storage Environment). Fluctuations in temperature and humidity — especially dramatic spikes — may release plasticizers or cause other chemical reactions that pose a direct threat to objects. If objects are not stable, consider storing them in cold storage, if possible. Just as cold storage helps preserve film-based collections, it will slow down degradation of cellulose acetate lamination.

Store laminated materials properly. Stable laminated objects should be stored in suitable archival enclosures (see Housing), such as buffered or acid-free folders and boxes (Figure 13), with interleaving to keep them from coming into contact with non-laminated materials. Laminated documents that are chipped, torn, or in pieces should be housed in a sturdy folder; small detached pieces should be placed in a marked acid-free envelope and kept with the object. Mylar encapsulation, though often used to protect fragile papers from handling damage, is never recommended for laminated papers. Encapsulation creates a microclimate that exacerbates the effects of any fluctuations in temperature or relative humidity and may speed up any degradation that might be taking place.

If the collection includes objects that are stuck together, they should carefully be separated from one another using a Teflon spatula (see Figure 6). Avoid touching exuded plasticizers with bare hands, and be sure to wash hands immediately afterwards. If necessary, the objects may be blotted carefully with cotton swabs. The separated leaves may then be housed as described above.

It is fairly common for books or notebooks to have been disbound, with each leaf individually laminated and then re-bound in post bindings. If the laminated pages are brittle or have begun to snap or tear, the post bindings should be removed and the pages stored safely as individual leaves. Label each page carefully in pencil on the laminated surface, to ensure that the correct order is maintained.

As with all rehousing, the addition of new enclosures will increase the size of the collection. You should allow enough room for lateral growth of the collection; one meter of material may expand to as much as two meters after rehousing.

Isolate deteriorated objects. Identify objects with different kinds of damage and physically separate them from other items. This is especially critical when there are signs of vinegar syndrome or other off-gassing, as the organic acids that are present can set off reactions in previously stable objects stored nearby, including some types of film and photographs. Negatives produced on "Safety Film" are made of cellulose acetate and are therefore just as susceptible to acid-catalyzed degradation as the laminate film. The gelatin layer of film and photographic prints may also be affected.

The amount of isolation necessary for safe storage depends on the number of objects involved and the amount of detectable off-gassing. If the off-gassing is extreme and the numbers are large, priority should be given to cold storage or a separate cabinet. If only one or two items show minor off-gassing, they should be placed in separate folders and boxes but may be stored near other materials. We recommend housing these materials in folders and boxes made of zeolite-containing stock, such as MicroChamber paper, that will trap gasses as they are released. Alternatively, the objects may be placed in cases that have charcoal filter inserts. Ensuring good air circulation will reduce the potential for damage by allowing off-gassing fumes to dissipate. If off-gassing and stable objects are stored in the same cabinet, regular monitoring is imperative.

Handle laminated materials carefully. Even though laminated objects may seem quite sturdy, they must be treated gently. Laminated papers that are currently stable may generally be handled with the same caution with which you would treat any archival document. If a document is extremely brittle or "crispy," it would be wise to strictly limit access; if it must be handled, provide additional support, such as medium weight blotter, heavy archival folder stock, or archival board or matboard. Digitizing, microfilming, photocopying, or otherwise re-formatting the collection can help reduce handling, although re-formatting raises important issues beyond the scope of this paper.

Do not attempt repairs to laminated objects. If a laminated object tears, chips, or is otherwise damaged, do not attempt non-archival repairs; pressure-sensitive tapes are as damaging for laminated objects as for other papers. Instead, create an appropriate housing for the object (see Housing). If some pieces are completely detached, label them carefully and store them in a suitable folder or envelope along with the rest of the manuscript. If repairs are necessary, contact a qualified paper conservator (see Finding a Conservator) Keep in mind that the presence of the laminate complicates standard repairs; conservators may need to use solvents and other specialized supplies.

Monitor laminated materials. All laminated objects should be monitored once a year, using both visual examination and the sniff test. The visual exam simply consists of checking objects for the signs of deterioration described above, such as warping, bubbling, splitting, or stickiness. Consider whether or not the condition of each object has changed visibly since the previous assessment. The sniff test is simply cautiously checking for the presence of any odor, such as the vinegar or ammonia smell typical of off-gassing laminate. It may be relatively hard to detect the odor coming directly from the object; instead, smell carefully when the folder or box housing the object is first opened to determine if there is a build-up of gas in the container itself.

This monitoring should only take a few minutes, but it is critical for ensuring that the collection remains as stable as possible. A policy of reporting any signs of deterioration in objects pulled for research or other purposes will also help in tracking each item's condition.

Consider delamination if necessary. When it is deemed necessary, conservators can usually reverse lamination. Delamination is a complicated process that requires a trained paper conservator working in a suitable laboratory stocked with specialized equipment and chemicals. The most common method used today, solvent immersion, is a rigorous process that can pose its own risks for objects. Soluble media, such as the aniline inks and dyes used in some fountain pens, copying pencils, and even ruled paper, may dissolve when exposed to the solvents used for delamination. The process may also increase the fragility of documents on poor quality papers, such as the high-lignin wood pulp papers that became common after 1850. If the objects to be delaminated are in particularly bad shape, they may need additional conservation treatments. Once delaminated, objects will need to be rehoused, which could result in a need for expanded storage space.

You may want to consider pursuing delamination if:

  • Objects are deteriorating and cannot be stabilized
  • There are significant aesthetic problems that prevent the use of the items.
  • There are issues of intellectual integrity, such as pages laminated together in the wrong order or misaligned pieces of a document.

 10_pixel_square.gif A word about stable laminated objects

In general, if an item is in relatively good shape and can be stored in a proper environment and housing, it may be prudent to simply monitor its condition and hold off on delaminating until it becomes critical, or until new treatment techniques are developed. Store the objects as recommended above and continue to monitor their condition. Should you need assistance, a professional conservator will be able to assess a collection's condition, provide advice on its care, and create a plan for preserving your documents.



General Information

The Smithsonian Center for Materials Research and Education (SCMRE) has information about storage conditions, handling, rehousing, reformatting, and other subjects that are pertinent to paper collections. Similar articles are available in hard copy in Storage of Natural History Collections: A Preventive Conservation Approach, Vol. I, edited by Carolyn L. Rose, Catharine A. Hawks, and Hugh H. Genoways.

Finding a Conservator

The American Institute for Conservation (AIC) is a professional organization that can provide information about locating a conservator in your area. Their Guide to Conservation Services is available on-line or directly from the AIC:

American Institute for Conservation
1717 K Street NW, Suite 200
Washington, DC 20006
Phone: (202) 452-9545
Fax: (202) 452-9328

Glossary of Lamination Terms


SCMRE- RELACT- Handling Paper Artifacts: Preservation Do's and Don'ts


SCMRE- RELACT- Introduction: Developing Solutions (especially Appendix V)

SCMRE- RELACT- Housing Descriptions

Storage Environment

Environmental Guidelines for the Storage of Paper Records (NISO TR01-1995) by William K. Wilson

National Information Standards Organization (NISO) technical report on suggested environmental conditions for storing paper-based records.

National Information Standards Organization, Preservation and Storage


Disclaimer  The information and recommendations provided here have been used by the Department of Anthropology in the care of its collections and are considered suitable as described; however, the Smithsonian cannot be held responsible should damage to your collection result from following these recommendations.

Credits Special thanks to Jane Stewart for providing access to collections in the Pennsylvania State Archives. Photography of that material is by Susan Peckham.


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