assessing a collection that may contain laminated materials,
the first step is simply to determine whether or not the materials
have been laminated. Papers laminated with cellulose acetate
can vary in appearance, but the easiest way to tell if a piece
of paper is laminated is just to examine it closely. If an object
was laminated without tissue, the cellulose acetate laminate
should be transparent, often with a shiny plastic look (Figure
8). The paper itself may have taken on a translucent quality.
If tissue was incorporated during lamination, the surface should
look dull or hazy (Figure 9), as if the entire object is seen
through a filmy cloud. Depending on the platen that was used
to apply pressure during the lamination process, the surface
of the object may be smooth or patterned, often with what looks
like a cloth weave (Figure 10).
After lamination, most documents were left with a narrow border
of laminate and tissue. These cloudy borders may extend up to
an inch from all sides of the sheet of paper, although they
were often trimmed to within 1/16” of the edge of the
paper (Figure 11). Such borders, which were considered desirable
as a means of increasing protection for the paper and making
leaves easier to bind together, are tell-tale indications of
lamination. Cellulose acetate lamination is only one of a host
of methods that have been used in attempts to strengthen paper
treatments may look similar superficially, so it is important
to examine papers carefully.
In addition to examining the objects themselves, it may be possible
to find documentation about their treatment. Treatment reports,
if they exist, should discuss the lamination process. In the
absence of formal reports, financial records such as purchase
orders or invoices may indicate which documents were laminated,
particularly if the lamination was contracted with an outside
party. In some cases, knowing when or where an object was laminated
may provide valuable information about the materials and the
process that were used; however, there was considerable variability
in the lamination procedure, even over a short time frame within
a single institution. The most important information remains
the condition of the object itself.
determine the condition of laminated objects, carefully observe
the collection. Signs of damage or deterioration include:
or inks that have smeared, run, or melted. Damage
to pigments and inks has occurred during the lamination process,
either through excessive heat and pressure or through chemical
reactions prompted by the process. If the document lacks other
signs of damage, it may currently be stable (see Figure
marks or burning. Scorching indicates that the
document was damaged by excessive heat during the lamination
process. If other signs of damage are not present, the object
may currently be stable.
strong vinegar or ammonia odor. A vinegar, ammonia,
tobacco, or cardboard odor indicates that the cellulose acetate
has begun to break down. Vinegar syndrome is a sign of active
deterioration, which cannot be stopped once it has started.
Any object with vinegar syndrome poses a direct threat for nearby
collections, as the off-gassing process may cause formerly stable
objects to begin deteriorating.
laminate Laminate that has warped, stretched,
curled, bubbled, cockled, or peeled away from the paper either
was not applied properly or has begun to deteriorate. As the
plastic deforms, it places stress on the paper encased within
it. In extreme cases, it may literally tear the paper apart
(see Figure 5).
or yellow paper. Discoloration suggests that the
object was not deacidified prior to lamination and is at risk
of damage from acids present in the paper (see Figure
or brittle laminate. Embrittlement is caused by
inherent chemical changes in the laminate, including deterioration
of plasticizers. As the plastic becomes less flexible, the object
will be increasingly vulnerable to tears and other mechanical
cracking, or snapping. Whether involving the laminate
or the document, this extreme form of embrittlement places corners,
bound edges, and other vulnerable areas of the document at risk
of becoming detached and eventually lost. The document is quite
fragile, and literally in danger of falling to pieces if handled.
or oozing surfaces. This indicates that plasticizers
are exuding from the laminate, placing the document at risk
of sticking to other objects. In the worst case, pages may be
adhered in a block, making them unusable.
tape or other inappropriate treatments. Some documents
were repaired with pressure-sensitive tape before lamination;
as the tape degrades, it will damage the document. Unless they
were done by a qualified conservator, repairs to documents after
lamination can also pose a risk to objects (see Figure
of Stable Laminate
laminated items do not have visible damage, are flat with little
to no planar distortion, and have little to no noticeable odor,
they can be considered stable. Remember that the lamination
process was quite variable, so even objects within the same
manuscript may differ greatly in condition and conservation
needs. To put it plainly, no two laminated documents will react
alike. Some may remain stable for long periods of time, while
others may rapidly degrade and endanger other objects.
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8. This document shows the shiny plastic look
common in laminated papers. 18th century land grants from the
Pennsylvania State Archives
Figure 9. This
page shows the dull, hazy look of lamination with tissue and
a matte laminate. Ledger book, 1866 By Roman Nose, Lakota
Figure 10. Detail
of laminated document, showing high surface gloss and some paper
texture. 18th century land grant from the Pennsylvania State
Figure 11. This
small sheet of notes shows the narrow, cloudy border of laminate
around the sides of the document. Maps and notes on place names
on the Baffin Island coastline, 1883 Franz Boas.
Figure 12. A map
mended with black tape prior to lamiantion. The products of
the tape's deterioration will be trapped within the laminate,
causing damge to the paper. 18th century land grant from the
Pennsylvania State Archives.
Figure 13. An
example of appropriate archival storage in archival boxes and
cabinets, with a stable environment. Artwork storage for the
National Anthropological Archives.