Hi moshe120,
Well, here we go (I hope this isn't more than you wanted to know!). A
good place to begin is at the Library of Congress website (I've copied
snippets which pertain to your question, but do click on the links -
there's alot more to think about than just acidity)...
Matting and Framing:
"Mat /mounting board should be made of cotton rag or chemically
purified wood pulp and must test negative for lignin. It should be pH
neutral (pH 7) or slightly alkaline (pH 8.5). The addition of
buffering agents to unpurified wood pulp papers does not render them
fit for preservation use. Colored board must not bleed and the color
must not rub off or fade. Board used for photographic materials must
have passed the photographic activity test (PAT). Yellowing board
suggests acid degradation and must be replaced to prevent damage to
the object."
http://lcweb.loc.gov/preserv/care/mat.html
Caring for Your Photographic Collections:
"Paper enclosures must be acid-free, lignin-free, and are available in
both buffered (alkaline, pH 8.5) and unbuffered (neutral, pH 7) stock.
Storage materials must pass the ANSI Photographic Activity Test (PAT)
which is noted in supplier's catalogs. Buffered paper enclosures are
recommended for brittle prints that have been mounted onto
poor-quality secondary mounts and deteriorated film-base negatives.
Buffered enclosures are not recommended for contemporary color
materials. Paper enclosures are opaque, thus preventing unnecessary
light exposure; porous; easy to label in pencil; and relatively
inexpensive."
"Suitable plastic enclosures are uncoated polyester film, uncoated
cellulose triacetate, polyethylene, and polypropylene. Note:
Photographic emulsions may stick to the slick plastic surface at high
relative humidity (RH); the RH must remain below 80% or do not use
plastic enclosures. Plastic enclosures must not be used for glass
plate, nitrate, or acetate-based negatives."
http://lcweb.loc.gov/preserv/care/photo.html
NPS Conserve-O-Gram index (PDFs)
Section 14: Photographs: 14/1 - 14/9
See Section 14/4: Caring For Photographs: General Guidelines:
http://www.cr.nps.gov/museum/publications/conserveogram/cons_toc.html
>>>>>>>>>>>>>>>>>>>
Another good website...
Minnesota Historical Society (MNHS)
Preserving your photographs:
http://www.mnhs.org/preserve/conservation/photpres.html
MNHS TechTalk newsletter PDFs:
Caring for photographic materials, Part I:
http://www.mnhs.org/about/publications/techtalk/TechTalkMay1998.pdf
Caring for photographs, Part 2:
http://www.mnhs.org/about/publications/techtalk/TechTalkJuly1998.pdf
Preserving Your Photographs:
http://www.mnhs.org/preserve/conservation/reports/photoqanda.pdf
>>>>>>>>>>>>>>>>>>
See Sections:
"How should I frame and display my photographs?"
"How should I store my photographic prints?"
http://www.archives.gov/preservation/archival_formats/photographs.html
>>>>>>>>>>>>>>>>>>
CARING FOR YOUR PHOTOGRAPHS:
"Keep photographic materials in enclosures that protect them from dust
and light and provide physical support during use. Chemically stable
plastic or paper enclosures, free of sulfur, acids, and peroxides, are
recommended. Plastic sleeves should be constructed of uncoated
polyester, polypropylene, or polyethylene. For most photographic
materials, unbuffered paper enclosures are preferred over buffered
enclosures. Alkaline buffering is added to archival storage papers to
absorb acidity from the stored material or the environment surrounding
it. However, some photographs may be altered by the buffering in
alkaline papers, so unbuffered paper is recommended for most
processes. Film-based negatives, which can produce acidic gasses as
they age, should be placed in archival, buffered enclosures and stored
separately from other photographic materials. Store cased objects,
such as daguerreotypes and ambrotypes, in their original cases or
frames with the addition of custom-made, four-flap paper enclosures to
reduce wear and tear on fragile cases. Place individually housed
prints, negatives, and cased objects in acid-free, durable boxes that
will afford further protection from light, dust, and potential
environmental fluctuations."
"Use unbuffered ragboard mats, and frame photographs with archivally
sound materials."
http://aic.stanford.edu/library/online/brochures/photos.html
>>>>>>>>>>>>>>>>>>>
Handling and Care of Photographs:
"Paper envelopes are a cheaper alternative to plastic sleeves. As with
plastic sleeves, not all paper envelopes are created equal. The
envelope should be acid-free and if possible lignin-free with a
neutral ph balance. Some archival envelopes have an alkaline buffer
which is a plus for long term storage. The alkaline is able to absorb
some of the more unstable elements from within (acid) and without
(pollutants from the atmosphere)"
"Alternative Cost Effective Storage: Another alternative storage
method which is quite common in many archives is for the
archivist/historian to preserve and store photographic images in
various sizes of acid-free folders and containers (manuscript boxes,
record center containers, etc.). If finances are not too tight
purcashing acid-free and lignin-free folders and containers should be
utilized. The archivist/historian should interleaf each image within
the folder with a sheet of acid-free paper. File folders containing
images should then be packed reasonably tight within the container.
This way "curling" of the image will not take place. This method is
especially useful when storing smaller oversize photographs in the
absence of flat file cabinets and mylar. The larger oversized
photographs can stored in various flat storage boxes and stacked no
more than five high on a standard shelf."
http://www.gcah.org/care.html
>>>>>>>>>>>>>>>>>>>
Additional Link:
Gaylord sells archival material but their catalogue is also instructional.
Gaylord Catalogue: Archival Storage of Photographic Materials:
"Since poor quality folders and envelopes can hasten the deterioration
of photographs
and negatives, it is essential that paper be free of acidic compounds such
as those found in alum-rosin sizing and unpurified wood pulp. It is also important
that the paper and boards used to store photographs have very low levels of
lignin (less than 1%) because lignin can cause staining and fading.
Acidity and alkalinity are measured by pH, using a logarithmic scale of 0?14,
where 7 is neutral. Paper should not have a pH below 7. In most cases, choose a
paper that has a pH of 7.5 to 9 and an alkaline reserve of 2-3% calcium carbonate,
which will neutralize acid contaminants that come in contact with the paper.
Some photographic processes, however, will react to alkaline environments. For
these materials, unbuffered paper with pH 7 to 7.5 is best for envelopes and
folders. In summary:
All papers used to store photographs should pass the Photographic Activity Test.
Nitrate and cellulose acetate film should be stored in buffered paper. Unbuffered
paper should be used for cyanotypes, including architectural blueprints and
dye transfer prints. The current ANSI Standard recommends unbuffered paper
for color photographs and color negatives; buffered paper for black and white
photographs and negatives.
Standards:
American National Standard for Imaging Media: Photographic Processed Films,
Plates, and Papers; Filing Enclosures and Storage Containers. ANSI Standard
IT9.2-1991.
American National Standard for Imaging Media: Photographic Activity Test.
ANSI Standard IT9.16-1994." [replaced with ISO 14523:1999 in 2000]
http://www.gaylord.com/pams/path3.pdf
ISO 14523:1999:
Photography -- Processed photographic materials --
Photographic activity test for enclosure materials:
http://www.eos.org.eg/web_en/cat/items/d24597.html
>>>>>>>>>>>>>>>>>>>>>
Photographic Media ? Storage Enclosures:
"Over the last number of years there has been ongoing research into
whether it is more appropriate to use buffered (above pH 7.0) or
non-buffered (pH 6.0 ? 7.0) paper enclosures for photographic media.
It now appears that the concerns about using buffered/alkaline
enclosures in direct contact with photographic media were unfounded."
http://aabc.bc.ca/aabc/newsletter/12_2/bc_archival_preservation_service1.htm
Northeast Document Conservation Center (NEDCC):
Assessing Preservation Needs a Self-Survey Guide:
"There are no standards governing the use of the terms
"archival-quality" and "acid-free"_and they are sometimes misused, so
read suppliers' catalogs and product descriptions carefully. If there
are questions about a product, ask the supplier
for details."
See Section B-4. Photographs and Negatives:
http://www.nedcc.org/selfsurvey/sec4a.htm
Northeast Document Conservation Center (NEDCC):
Preservation supplies & services -- photographic supplies:
http://www.nedcc.org/suppliers/suppho.htm
Iowa Conservation and Preservation Consortium:
Tips on Preserving Photographs:
http://www.uni.edu/petersog/icpctip5.html
Standard Paper For Permanent Record:
http://www.cslib.org/permpapr.htm
Nat'l Archives of Australia: Advice 30 - Which Paper?:
...general discussion of paper types:
http://www.naa.gov.au/recordkeeping/rkpubs/advices/advice30.html
CoOL: Conservation/Preservation Information for the General Public: Links:
http://palimpsest.stanford.edu/bytopic/genpub/
United States Government Printing Office:
Government Paper Specification Standards:
Part 1: Printing Paper
Uncoated Permanent Book, White and Cream-White (Archival Quality)
Part 2. Testing Standards and Definition of Terms
http://www.access.gpo.gov/qualitycontrol/paperspecs/index.html
GPO quality control - paper specs:
http://www.access.gpo.gov/qualitycontrol/paperspecs/part4/129.pdf
I hope I've been able to sort this out for you and your photos will
soon be safe and sound in storage. If you have any questions, please
post a clarification request before closing/rating my answer.
Thank you,
hummer
Google Search Terms Used
"preservation of photographic prints"
"preserving photographic prints"
"acid-free paper" specifications
We mostly made extensive use of our own bookmarks. |
