 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.
|
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.
| 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.
Resources
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
E-mail:
info@aic-faic.org
Glossary
of Lamination Terms
Handling
SCMRE- RELACT- Handling
Paper Artifacts: Preservation Do's and Don'ts
Housing
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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