THE CARE AND PRESERVATION OF
Mary Fahey, Head of Preservation/Chief Conservator, The Henry Ford
Virtually everyone has a collection of Archival Materials that
require preservation, whether they are sentimental, financial, or
educational materials . Archival collections can be preserved for
years of use provided that some basic care is given to their preservation.
The conservation staff at the Henry Ford Museum and Greenfield Village
have compiled the information in this fact sheet to assist in promoting
the responsible care of archival collections. The first step in
the care of collections is to understand and eliminate or minimize
conditions that can cause damage. The second step is to follow basic
guidelines for care, handling and cleaning.
The Nature of Archival Materials
and Parchment Supports
and Ground Materials
Factors that Cause Damage
Storage, Exhibition, and Framing
Repair and Cleaning
THE NATURE OF ARCHIVAL
Archival collections can be divided into three basic types: individual
documents, books and photographic materials.
This information sheet addresses issues associated with the preservation
of documents and books. For information concerning photographic
collections see the listing of available conservation information
Documents generally consist of
three basic components: the paper or parchment support upon which
information is recorded, a sizing material or ground layer that
covers the surface of the paper or parchment, and the media that
is applied to the support to create the document.
PAPER AND PARCHMENT SUPPORTS
Most paper consists of cellulosic materials. There are a variety
of plants that can serve as sources of cellulose for paper making;
which, in addition to hard and soft wood, include: linen, hemp,
cotton, and mulberry.
Prior to the 19th century paper was made by hand. Most paper consisted
of cotton, hemp, linen or mulberry fibers. Paper that is made from
these fibers is commonly referred to as rag paper. Rag papers are
generally very durable and can be preserved for hundreds of years.
With the dawn of the modern paper industry in the early 19th century,
wood-based papers became an abundant and inexpensive alternative
to costly rag-based papers. As with many inexpensive materials,
cost efficiency did not coincide with durability.
Wood-based papers are prone to degradation due to the presence
of lignin, which if not removed during the process of paper manufacture,
degrades to form acidic compounds. The presence of these acids
causes the paper to degrade rapidly becoming yellow and brittle,
eventually leading to total disintegration. Modern newsprint paper
is an example of wood-based paper.
Parchment and vellum are made from the skins of small animals.
Traditionally, the skins are treated with slaked lime which acts
as a preservative. The skin is then rubbed smooth with an abrasive
such as chalk or pumice. Generally, parchment refers to the skin
of sheep and goats, while vellum refers to fine quality skins
that are obtained from calves, kid or lambs.
SIZING AND GROUND MATERIALS
Sizing refers to the application of adhesives, such as gelatin,
plant gums or starches, to the surface of a sheet of paper. Unsized
paper is highly porous and absorbent making it unsuitable for
use with media such as ink and watercolor paints. Sizing is added
to make the paper surface less absorbent in order to prevent the
bleeding and blurring of media and to provide additional strength.
In the early 16th century, alum (potassium aluminum sulfate) was
introduced as an additive to gelatin sizing, which served as an
effective hardening agent. Unfortunately, alum degrades to form
sulfuric acid, which leads to the eventual degradation of the
Processes such as printmaking require the use of paper having
an extremely smooth surface. A ground layer consisting of clay,
chalk or pigmented materials which are held together by an adhesive
can be applied to the paper to give the required smoothness for
Media refers to the materials that have been used to create the
document. Some commonly used media include watercolor paints,
pencil, chalk, and ink which has been applied through a variety
of printing or writing techniques.
Iron gall ink, which has been in use since the medieval age, degrades
at an exceptionally rapid rate due to its chemical composition.
This ink is manufactured from a mixture of oak galls and ferrous
sulfate. As it ages, the ink emits sulfuric acid which eventually
destroys the underlying paper support.
Books can be viewed as having three basic components: (1) pages
or leaves consisting of parchment or paper; (2) a protective covering
made from leather, parchment or fabric; (3) the media that has been
used to create the document.
Paper and parchment leaves can be bound together by a variety of
different methods including sewing, stapling or attachment with
Both flexible and rigid book covers comprised of leather, parchment
and fabric have been used over the years. In general, for rigid
covers, cardboard, pasteboard and wood have been used as the underlying
support. Pasteboard is a rigid material that is made by lamination
of leather and parchment scraps.
Leather has been used for the manufacture of book covers since medieval
times. Leather is made from a variety of animal including: cattle,
pigs, deer and sheep. For the majority of book coverings, tanned
leather was utilized. Tanning refers to a process by which leather
is chemically treated in order to impart strength and stability.
A variety of tanning processes have been developed over the years;
each of these processes varies in its effect upon the longevity
of the leather.
Leather that was produced prior to the 17th century using a vegetable-tanning
process has proven to be highly stable. However, much of the vegetable-tanned
leather that was produced during the 19th century is particularly
unstable and prone to the development of Red rot. Red rot appears
as powdery red degradation that is caused by the presence of sulfuric
acid in the leather. During the mid-1800's, an increased demand
for leather goods led to the development of a variety of new processes
which vary in stability.
PARCHMENT AND VELLUM
Parchment and vellum were widely used for written materials up
until the 19th century. Like leather, parchment and vellum are
manufactured from animal skins. Both materials are extremely strong
and durable; however, they are highly sensitive to moisture changes.
Parchment and vellum undergo dramatic expansion and contraction
corresponding to absorption and evaporation of water which leads
to the formation of wrinkles and puckers. When utilized as coverings
over wood or cardboard, this instability can lead to warping and
distortion of book covers.
In recent times, the use of fabric and paper has increasingly
replaced leather as book covers. Sized linen or cotton fabric
is frequently used. Bookcloths, which were first manufactured
in England in the early 1820's, were sized with starch which imparted
rigidity and resistance to water damage. In 1910, pyroxylin-treated
fabric came into use; however, these cloths were found to be unstable.
Acrylic materials are becoming a common replacement for the traditional
starch-based sizing. Other fabrics that have been used as cloth
covers include silk and velvet.
FACTORS THAT CAUSE DAMAGE
There are a variety of factors that contribute to the degradation
of archival materials. These include careless handling, poor environment,
inappropriate storage, exhibition or framing, and improper cleaning
Careless handling is by far the most prevalent cause of damage to
archival materials. It can lead to tears, wear, loss of the image,
creases and staining. The following guidelines are included to assist
in the prevention of damage that can occur during handling.
- Clean white cotton gloves should always be worn when handling
a book or document. Salts and oils from human hands can cause
damage in the form of staining and can also transfer dirt to
the paper surface. Cotton gloves can be purchased from conservation
suppliers (see supply list). If gloves are not available, care
should be taken to ensure that hands are washed and dried frequently
when handling the art.
- All work spaces and table tops should be neat and free of
- When moving a paper or parchment document always support it
from below. The safest method for moving the object is to slide
a piece of stiff paper or matboard underneath the art so that
the matboard (not the document) is handled. This is particularly
necessary when handling brittle paper or parchment items that
cannot support their own weight. Never lift a piece of paper
by its edges, particularly if there are any tears present.
- Stacked paper objects should never be dragged or slid across
each other. This can cause abrasion or smudging of their surfaces.
It is preferable to lift them up one at a time.
- Books should be grasped by both sides, not by the upper edge
of the book (endcap). This can lead to damage and tearing of
the binding. If the sides of the book are not readily accessible
(as is often the situation with books that are stored on book
shelves), the book should be gently nudged forward on the shelf
from the back so that it can be fully grasped with one hand.
- Never eat, smoke or drink in the vicinity of archival collections.
Accidents can lead to irreparable staining or burns.
- It is a good rule to use only pencils when working on, or
around, archival materials as pens and markers can cause staining.
Never write on documents with a marker or pen. It can bleed
through to the other side or can complicate future conservation
- Paper clips, binder clips and post-it notes should not be
used on archival materials. Metallic clips can corrode and leave
rust stains on paper, parchment and fabric. Post-it notes can
damage the media or paper surfaces.
- Extensive xeroxing of books and documents should be avoided
as it can lead to damage in the form of fading. The compression
of books during xeroxing can also break the binding and spine
of the book.
The overall environmental conditions under which archival materials
are stored and displayed can have a great effect upon their longevity.
Factors that can lead to damage include: pollution; pests; and
inappropriate temperature, relative humidity and light levels.
Pollution - The fading of
dyes and pigments and the overall degradation of archival materials
can be caused by a variety of pollutants, including sulfuric acid,
nitric acid, ozone and formaldehyde. These chemicals can originate
either from the outside air or from materials in the environment.
Wood and leather, as well as some rubber and plastic materials,
can produce acid vapors as they age.
Air filtration is the most effective way to minimize damage due
to pollution. Proper storage can help to prolong the life of works
of archival materials, if air filtration is not feasible.
Measures should also be taken to eliminate storage or display
in the vicinity of materials that emit hazardous gases. Unfortunately,
for composite objects such as books, incompatible materials such
as leather and paper cannot be separated. (see proper storage
Pests - There are a variety of insects
that can damage paper and leather artifacts; primarily, silverfish,
firebrats, carpet beetles and the book louse.
Silverfish feed on mold and starchy materials that are found
on paper. They are small gray insects (approximately 12mm
in length) and have a scaly appearance. Silverfish are generally
found in dark, cool and moist environments such as basements.
Evidence of silverfish damage is visible as an abraded rough
surface on paper materials.
The firebrat is similar in appearance to the silverfish;
however, it is somewhat darker in color. Like silverfish,
firebrats also feed on mold and starchy materials; the major
difference being that firebrats prefer environments which
are warm, moist and dark.
The book louse is generally found in heated buildings. They
feed on mold spores that are found on paper and cardboard.
Direct feeding by book lice doesn't cause visible damage
to paper; however, their squashed bodies can cause staining.
Book louse prefer high humidity levels (above 60%), and
they reproduce at warm temperatures above 25 degrees C.
Carpet beetles generally subsist on protein-based materials
that are often present in archival objects; i.e., adhesives,
leather or parchment. The presence of tiny black beetles
(2mm in size), small worms or furry carcasses are an indication
In general good housekeeping is the best method of deterrence.
Regular inspections of stored collections provides the cheapest
and safest method of safeguarding against infestation. Screening
on windows and doors will aid in keeping out larger pests.
In addition, fresh flowers and plants should be inspected
before being brought into the home. When infestations are
suspected, sticky insect traps can be placed under cabinets
and cupboards. These traps do not poison insects, but they
do aid in assessing the numbers and types of insects that
In general, insecticides should not be used on or in the
vicinity of archival materials. Insecticides can cause the
fading and discoloration of paper, leather or parchment.
If you do find an infested item, place in sealed plastic
bag and contact a professional immediately.
Temperature and Relative Humidity -
Fluctuations and extremes in temperature and humidity levels
can have a detrimental effect upon the preservation of archival
materials. By far, the greatest damage to collections is caused
by rapid fluctuations in relative humidity.
Temperature and humidity are interrelated. In general, heated
buildings have very low relative humidity levels in winter.
Conversely, humidity levels are high in the summer months.
Low humidity levels can cause:
- the drying out and embrittlement of materials.
- the shrinkage of vellum and parchment covers, resulting
High humidity levels can cause:
- the swelling of paper and parchment materials, resulting
in planar distortions.
- coated papers to stick together
- the transfer of inks from one surface to another.
- mold growth in levels above 60%.
Ideally cool storage is desirable for archival materials; however,
in the home, it is generally not practical. Therefore, damage
should be minimized by avoiding extremes in temperature and
humidity. This can be done by insuring that objects are kept
away from heat sources such as furnace vents, fire places, warm
lights and direct sunlight.
Excessive humidity, as can be found in most basements, should
also be avoided since it can cause mold growth that can stain
the surface of the object.
Recommended temperature and humidity levels for the storage
and display of collections are as follows:
Temperature: 67 degrees F, plus or minus 2 degrees F
Humidity: 47%, plus or minus 2%
Inexpensive temperature and humidity sensors can be purchased
from University Products Inc. (See Suppliers).
Light - Another major cause of damage
to archival materials is exposure to high light levels, which
leads to fading of media, discoloration and embrittlement due
The most damaging portion of natural and artificial light is
Ultra Violet (UV). UV is the invisible high energy portion of
light. This is the same energy that has been proven to damage
eyes and skin. UV filtering for windows and frames is commercially
available and can significantly reduce the damaging effects
of UV light.
In addition to damage resulting from exposure to UV, visible
light can also damage documents. The recommended light levels
for display of paper materials in museums is very low. 50 LUX
is the level that is recommended for short periods of time (6
months). Colored inks are among the most susceptible to light
damage and should be displayed in dim areas, free from bright
light sources. Media such as black ink can tolerate somewhat
higher exposure levels.
A camera light meter can be used to read visible light levels
within your home; however, this method cannot be used to record
UV levels. See CCI IIC Notes 2/5.
STORAGE, EXHIBITION AND FRAMING
The proper storage and display of archival materials can help to
minimize many of the factors that can lead to degradation.
- Paper Documents
The encapsulation of documents within a clear plastic (mylar)
envelope provides a simple method of protecting documents
from dirt, dust and tearing. Encapsulation also allows for
viewing of both sides of the document. Mylar envelopes and
acid free boxes can be purchased from conservation suppliers.
For large or odd size documents, sheets of mylar can be sewn
together or adhered along the edges using double sided tape.
The recommended tape is 3M #415 adhesive tape. Care should
be taken to insure that the tape does not come in contact
with the document. Encapsulated documents can then be placed
into acid free boxes or folders for long term storage.
Items that are not handled often can simply be placed in folders
and boxes. All storage boxes, paper folders and tissue paper
should be acid-free, lignin free and have a neutral pH. Acid
that is generated by poor quality wood-based cardboard boxes
and folders can cause the degradation of artworks stored within
Severely degraded paper should be stored in buffered boxes
that contain an alkaline reserve. Alkaline reserve buffers
are chemicals that absorb acids that are generated by the
In general, good housekeeping is essential to the preservation
of artworks on paper. Routine inspection and cleaning of boxes
and folders will aid in extending the life of collections.
Parchment documents should be stored in unbuffered acid
free folders or boxes. The use of mylar folders is not recommended
Bookshelves are the most common method of storing books.
To minimize damage that can be caused by overcrowding, books
should be packed loosely on shelves. The use of book ends
can help to provide even support. Large books should be
stored flat on shelving units. Rare and fragile books should
be placed into individual protective enclosures (see CCI
IIC notes 11/1).
Exhibition and Framing
The display of documents and books in the vicinity of fireplaces
or air ducts should be avoided since dirt and soot can be
deposited onto the paper surface. The display of framed
documents on exterior walls should be avoided as it can
lead to damage resulting from moisture condensation on the
back of the document.
Matting and Framing
Archival documents can be framed for display. The use of
high quality, acid-free, lignin-free matboard is recommended.
In general, paper objects should be framed using a window
mat. Window mats provide space between the surface of the
artwork and the glass of the frame to prevent the work of
art from becoming stuck to the glass surface (see CCI IIC
Notes on Framing 11/5).
The document should be attached to the matboard using only
acid-free paper hinges and high-quality adhesives. Staining
can be caused by contact with acidic or other poor quality
materials, such as scotch tape or rubber cement. The recommended
adhesives for hinging paper are wheat starch paste, methyl
cellulose, and the ready-made paper framing/hinging tape
that is available from University Products Inc.
The use of ultra violet filtering glass and Plexiglas in
frames can help to reduce damage from UV light.
REPAIR AND CLEANING
Aside from obscuring text, dirt can attract moisture, mold spores
and pollution. Dirt also has an abrasive quality that weakens the
structure of leather and paper.
In general, the cleaning and repair of paper materials should be
carried out by a professional conservator. If you wish to carry
out some surface cleaning, the following procedures should be followed:
Paper and parchment documents can be lightly dusted with a soft
brush to remove surface dirt. Prior to dusting, the art should be
inspected carefully to insure that there is no loose or powdery
media or surface that could be brushed away during cleaning. Any
additional cleaning of parchment should be carried out by a professional
If brushing does not remove sufficient surface dirt, dry eraser
pads such as Opaline and Skum-X can be used on paper. Again, this
method of cleaning should only be used for stable images.
To clean with Opaline or Skum-X, simply shake the powder onto the
surface of the document and very gently rub it over the surface
of the paper. The powder should then be brushed off using a soft
brush. Care should be taken to clean only the areas around the media,
not the media itself.
Always proceed with caution when cleaning. Over-cleaning can cause
more damage than the dirt itself. Extensive wet or solvent cleaning
should only be carried out by a conservator.
The covers and edges of books can be brushed to remove surface
dirt. An alternate method of cleaning is the use of a low-suction
portable vacuum. A soft brush attachment and nylon screen should
be attached over the end of the nozzle to catch loose fragments
that could be vacuumed up during cleaning. All fragments should
be saved since they can be reattached during future conservation
Archival materials that have been stored in damp environments
are highly susceptible to damage by mold growth. In situations
where mold growth has occurred the mold must be removed before
it can cause permanent staining or contamination of other objects.
The safest method of mold removal for paper items is the use of
a brush and a small low-suction vacuum cleaner. Mold spores can
spread through the air and must be contained. The Canadian Conservation
Institute has devised an inexpensive method of making a vacuum
that traps mold in a glass vial containing water (see CCI IIC
If a vacuum cannot be constructed, an alternative method is to
brush the mold off the surface of the paper. This must be carried
out in an area where other paper and objects will not become contaminated.
During the summer, this work could be done outdoors. Frequent
cleaning of brushes is essential.
Place artwork in stable environment with moderately low humidity
level and monitor its condition.
Ann Clapp Intermuseum Conservation Association. The Curatorial
Care of Works of Art on Paper. The Intermuseum Laboratory
- Allen Art Building. Oberlin, Ohio 44074
Dolloff, Francis W., and Perkinson, Roy L. How to Care
for Works of Art on Paper, 2nd ed. Boston Museum of Fine Arts,
Ellis, Margaret Holbein. The Care of Prints and Drawings.
Nashville: American Association for State and Local History, 1987.
Timmons, Sharon, ed. Preservation and Conservation: Principles
and Practices. Washington, DC. The Preservation Press, 1976
Zigrosser, C., and Gaehde, C.M. A Guide to Collecting and
Care of Original Prints. New York: Print Council of America,
Keyes, Keiko Mizushima. "The Unique Qualities of Paper as
an Artifact in Conservation Treatment", The Paper Conservator,
The United Kingdom Institute of Conservation. Modern Art: The
Restoration and Techniques of Modern Paper and Prints. 37
Upper Addison Gardens, Holland Park, London W148AJ. 1978.
Ritzenthaler, Mary Lynn. Archives and Manuscript Conservation.
Basic Manual Series Society of American Archivists, Chicago 1983
Kathpalia,Y. Conservation and Restoration of Archival Materials.
Cunha, Dorothy. Conservation of Library Materials.
The Scarecrow Press, Inc. Metuchen, N.J., 1971
Cuhna, Dorothy. Library and Archives Conservation: 1980's and
Beyond. Vol. I. The Scarecrow Press, Metuchen, N.J. 1983
Kansas City Area Archivists. Keeping Your Past: A Basic Guide
to the Care and Preservation of Personal Papers. Western Missouri
Publications Committee, 1987
American Library Association. Cleaning and Preserving Bindings
and Related Materials. 2nd ed., 1982
For a concise description of paper making see:
Papermaking: The History and Technique of an Ancient Craft.
New York: Knoft, 1967; reprint ed. New York, Dover Publications.
American Institute for the Conservation of Historic and Artistic
Works. Book and Paper Group, Annual Publications 1990, 1993
Conservation of Historic and Artistic Works on Paper. Proceedings
of the Conference Symposium, 1988. Sponsored by the Canadian Conservation
Institute, Ottawa, Canada 1994
Stolow, Nathan. Conservation and Exhibitions. Butterworths,
Kuhn, Hermann. Conservation and Restoration of Works of Art
and Antiquities. Butterworths, London 1986
Zycherman and Schrock, C. A Guide to Museum Pests.
American Institute for the Conservation of Historic and Artistic
Works. Washington, DC 1988
Pinniger, David. Insects and Pests in Museums. Archetype
Storage and Display
ICC CCI Notes
Canadian Conservation Institute Notes
1030 Innes Rd.
Ottawa Ontario Canada K1A 0M8
11/2 Storing works of art on paper
11/5 Matting works of art on paper
11/1Protective enclosures for books and paper artifacts
Margaret P. Brown. Polyester Film Encapsulation. Preservation
Office Services, Library of Congress
Washington, DC 1980
517 Main Street
PO Box 101
Holyoke, MA 01041-01011
Framing supplies, temperature and humidity sensors
439 Monroe Ave.
PO Box 940
Rochester, New York 14603-09401
Conservation Resources International LLC
8000-H Forbes Place
Springfield, VA 22151
(703) 321-0629 (fax)
For a listing of conservators in your area, please contact:
The American Institute of The Conservation of Historic and Artistic
717 K Street NW
ashington, DC 20006
Copyright © 1995-2000
The Henry Ford ~ www.TheHenryFord.org