X-Message-Number: 5591
Date: 14 Jan 96 04:41:04 EST
From: "Steven B. Harris" <>
Subject: SCI.CRYONICS Color Film Archiving
Dear CryoNet:
In the spirit of trying to cure the recent amnesia on this
topic, I am offering below a re-written article, based on one
last posted to the CryoCare list Sept 13, 1995. It's only half a
repost, however, for since this time I have had to do a great
deal of updating and revising, having newly acquired the bible of
film preservation: _The Permanence and Care of Color Photograph-
s_, 744 pp., by Henry Wilhelm (with some material by Carol
Brower), available from Preservation Publishing Co., Grinnell,
Iowa (515-236-5575). This excellent book is a labor of love by a
man who has spent his life doing fading tests on papers and
films, and trying to keep companies like Kodak honest about the
archival qualities of their photographic products. I heartily
recommend it for serious students as being a much superior
information source to pieces of propaganda like the official
Kodak publications (eg. _Conservation of Photographs_ Kodak
Publication F-40).
Here are some updated recommendations for color film archivi-
ng, then, based on Wilhelm's work. Among the interesting things
to be discussed is the availability of polyester-based color
films and papers which are stable in the dark for centuries, even
without special care.
-----------------------------------------------------------
COLOR PHOTOGRAPHIC ARCHIVING
Steve Harris
I notice that there have been a few comments about film which
have not made much distinction between film and prints. Film is
the stuff that goes in your camera as a cassette, and which you
get back in strips from the photo store (unless you have a
"instant print" camera like the various Polaroid instamatics; but
no instant print film is any good for archiving, so forget this
option). For film which requires developing by a commercial
color processing lab, you have a choice between slide and print
film. With slide film, the film itself is developed as a
positive (color transparency), and that's what you get back from
the lab, cut up in frames, in those little cardboard holders to
be projected as "slides" (you can also get it in a positive
coiled strip, if you ask, as noted below). With "print" film,
the film is developed as a color negative, and your prints are
developed by projecting light through the negatives onto
photoreverse color paper. Here you get back both prints and
strips of color negatives. Some people make the mistake of
tossing out these negatives, but no cryonicist who has thought
seriously about the problem will make that mistake (at least not
after you read this article!)
We will discuss 35 mm films, which because of small size and
large variety will be the most common films stored by the non-
professional photographer. The most common 35 mm films are
print films, and generally any film which ends with the suffix
"--color" is a print film. The Fujicolor, Kodacolor (Gold),
Vericolor and Ektar series, are all print films. All are
developed by a standard E-6 type one-step process, and are the
kind of thing you can get done in a "One-Hour" photo-store. They
are generally printed on standard photographic paper (which
varies widely in quality, by the way). For archival purposes,
most of these E-6 films and papers are not very good, with
exceptions to be noted below.
COLOR PRINT PAPER
As for the PAPER, standard prints on the Kodak papers of today
begin to lose color in a decade or so, depending on the paper and
its care. For many papers of even a few decades ago, the loss
rate was far greater. The loss for any paper happens faster if
the print is stored in stickup store-bought "zip" photo albums
against gummed acid paper, or out on display where UV from sun or
fluorescents can damage it. Air quality is also important-- for
instance hydrogen peroxide released from free radical oxidation
of unsaturated oils in wood finishes, and in fresh oil-based
paints (linseed oil especially), causes rapid destruction of
prints at relatively tiny air concentrations. (Thus, when you
paint with oil-based paints, get all photographic prints out of
the area for the next several months. Latex paints do not cause
problems).
Fading happens less quickly under tungsten illumination
(intermittent viewing in albums), and far less with prints stored
in all-polypropylene-plastic pocket archival-quality folders (or
in acid-free boxes interleaved with Tyvek, or with acid-free,
buffer-free, lignin-free paper), away from unsaturated oils, and
at the proper relative humidity (about 30%). Generally, however,
the print is not usually what is archived anyway. Prints are for
display and are usually assumed to have a limited life. They are
bulky, and archival quality prints from negatives that need long
life and stable colors are *quite* expensive, and often have
easily damaged surfaces. Archival color prints from slides are
available in Cibachrome (now called Ilfochrome) or Fujichrome
processes. For color negatives the current best printing product
is Fujicolor SFA3 portrait paper, which is expected to last 40-50
years in normal display before fading, considerably longer than
illuminated Ilfochrome prints, and at less cost. Since Fujicolor
SFA3 prints last 4 times as long under illumination as those on
standard Kodak Ektacolor paper, they are highly recommended for
printing of color negatives you want to look at more than 10
years from now.
The Cadillac of archival color printing (just to show this
isn't quite an oxymoron) is the process represented by the very
interesting Ultrastable Permanent Color Prints (UltraStable
Systems, Inc, Santa Cruz, CA) and Polaroid Permanent Color
Prints, both made with a unique and different pigment system, and
expected to last up to 500 years. "Permanence" does not come
cheap, however: a 16 x 20 UltraStable portrait may be as much as
$500.
FILMS
E-6 processed color negatives hold up better than many
standard color prints on paper, but even here the life varies
widely. Kodak has long been very cagey about releasing
stability estimates for its films, but independent tests and some
information from the company indicate that none of the color-
negative E-6 films are suitable for room temperature archival
material, and the previous color negatives, dating before the mid
1970's, were worse. The older Kodacolor VR and the slower Ektar
and Vericolor professional films have dark "lives" (which we
define very conservatively as until just noticeable fading of the
most sensitive yellow dye occurs), of only about 12 years, and
the new Kodak Gold and faster Ektar and Vericolor films no more
than 20-30 years (Vericolor films generally fared worst of all at
every ASA rating, with the exception of Vericolor III pro-
fessional film type S, which has a life of 16 years). None of
this is any good across even a reasonably long life, let alone
for cryonics purposes.
One can also buy 35 mm slide films, which give a direct
positive transparency, but which can (if necessary) also be
printed to make paper prints with a photo-reverse process. Films
which end with "-chrome" are slide films: Fujichrome, Ektachrome,
Kodachrome, etc. All but Kodachrome are also developed with the
quick and standard E-6 process (slides in an hour). These slide
films represent a considerable improvement in stability.
Least stable of the slide films, but still considerably better
than color print films, are the standard Ektachrome slide films
(Group I Ektachromes), introduced 1979, which have estimated
lives of 52 years under the above conditions; and the group II
(high color saturation) Ektachrome Plus and Ektachrome HC films,
introduced 1988. These latter have an estimated life of 110
years, but H. Wilhelm states that when their more rapid formation
of yellow stain is taken into account, they do no better than
standard Ektachromes. Fujichrome slides are another choice--
they are about as stable as Ektachromes in the dark, and during
projection are the most stable of all the color slide films.
The most dark-stable of all photographic films (as opposed to
microfilms), and the one which has been best tested in actual
time (rather than accelerated aging tests), is the slide film
Kodachrome, which is amazingly close to the original color film
introduced by Kodak in 1937. Kodachrome (now available in ASA 64
and also newer 200 speeds) is developed in a rather complicated 3
step process (K-14), and must be sent for development to a
professional lab such as Kodalux, not your corner photo store
which does only E-6 developing. The reward, however, is slide
film which is exceptionally stable in dark storage: many old
Kodachromes which have not been mistreated (dark-stored in a
cool, dry place, and not shown in a projector a total of more
than 20 minutes) look pretty much unchanged after 50 years. The
estimated dark-storage "life" of all types of Kodachromes is an
estimated 95 years at 75 F and 40% relative humidity. This is
the life to even minor degradation of the image.
As noted, Kodachrome cannot be projected much-- it actually
has the worst projection fading qualities of all the films.
Thus, it should be used as an archival film only, since it has
only enough illumination life to hold up to making prints and
second copies. You should NEVER project primary film copies of
anything you intend to keep anyway. If you want to do much
public viewing of positive color transparency material which
you've archived, you'll want to have photoreverse prints made
from it, or else slide copies on Fujichrome (which is twice as
light-stable as KodaChrome), for projection. Again, the rule is
that you never want to view archival material itself much, except
briefly under low tungsten illumination such as a hand slide-
viewer to see what you have-- otherwise it's only for making
copies.
It takes a bit more space to store normal slide film than
print film negatives, but (again) if you specify it, you can have
positive Kodachrome film processed and supplied in strips, like
print negatives, unmounted. This is more convenient for
evaluating film archival materials directly when the prints are
not available or easily indexed, and is certainly more convenient
for evaluating archival materials if refrigeration of transpar-
encies can be avoided by use of slide rather than print film
(which it usually can). For slides, use of Kodachrome as opposed
to Kodak Ektachrome or Fujichrome has the drawback of being more
expensive and taking much more processing time than the standard
E-6 processing, but (as noted) results in slides with twice the
lifetime of Ektachromes or Fujichromes. Of all the primary
photographic films discussed, only Kodachrome can be said to have
a good shot at being a cryonics archival film under ordinary
"good" house storage conditions (such as in a closet in a an
always cool part of a house in a dry climate). The other slide
films are viable choices for archival photographic storage in
humidity controlled mines, and indeed only Ektachrome is the
choice for low cost slide duplicating film (more about this
later).
Among film duplicating media, a color micrographic film called
Ilfochrome (to be discussed) seems to be the film of choice for
dark storage of ANY color image over time. Black-and-white
microfilm (used to store print, due to low cost) is more stable
than standard acetate color slide film, and should have endurance
times of several centuries even at 75 F. Wilhelm reports that
one outstanding polyester-base color microfilm (Ilford Ilfochrome
Micrographic film, called Cibachrome Micrographic film from 1984-
1991) has dark storage characteristics far better than Kodachro-
me, and probably even better (according to Wilhelm) even than
standard black-and-white microfilms. Ilfochrome does fade in
light, as do all films, but has a dark-endurance time of many
centuries (nobody know how many because it ages so slowly). This
means Ilfochrome comes close to being the legendary permanent
dark-stable color film, holding up without any significant
degradation in rapid-aging tests, long after all conventional
acetate base films yellow and fall to pieces. Unfortunately,
Ilfochrome cannot be used as a primary photographic film, due to
being far too slow (ISO ~1). Ilfochrome (Type P) is sometimes
used as a slide duplicating film, however, so that it is possible
to reprint slide photographs onto this film without reduction,
for a process in which a truly superior archival product is
generated (I can't give the cost for this at the moment, but it
is significantly higher than for standard slide duplication).
Needless to say, Ilfochrome color microfilm can also be used
for microfilm reproduction of colored graphs, maps, diagrams,
schematics (Type M is used); and also reduced-size color photos,
for photos in which great detail isn't needed (i.e., this is an
intermediate option between saving and not saving a color
photo!). Ilfochrome is distributed and processed in the US by
Microcolor International, Midland Park, New Jersey (201-445-
3450). They also offer various micrographic services.
REFRIGERATION AND CLIMATE CONTROL
How long can unstable films be kept in good condition if
special precautions are taken? Tests suggest that the Arrhenius
relation for most films is a doubling of life for every reduction
of 9 F or 5 C. This means that film decay can be slowed (rela-
tive to that at 75 F) by a factor of 2 at 66 F, by a factor of 4
at 57 F, and a factor of 16 at 39 F. We will see the implica-
tions of this below.
Relative humidity (RH) is also important. Film degrades
quite quickly above RH of 50%, and 20-30% is optimal (providing a
life increase of a factor of 2 from 50%). Relative humidities
below 15% are not recommended, since they tend to dry and crack
film emulsions away from the film stock (the emulsion is the
silver and dye-containing gelatin layer which actually holds the
photographic image).
There are two standard choices for storage of photographic
materials in controlled circumstances. The first is climate-
controlled mines. I do not have a list of these, but I was able
to find that the commercial venture called National Underground
Storage, Inc., located 220 ft. down in a salt mine near Boyers,
Pennsylvania, maintains a constant 68 F at 25% RH (this mine is
where the majority of routine government records are stored, and
also many Hollywood films). The temperature and RH numbers at
National Underground should be good for a factor of three in
degradation rate relative to our reference values for 75 F and 40
RH. Properly packaged Ektachrome (acid-free and residue-free
envelopes and boxing) should thus be good for at least ~150 years
under these conditions, and Kodachrome for ~300 years. I will
conservatively estimate that endurance times of > 150 years may
be sufficient for cryonics purposes, and > 300 years very
probably. Note that this is for standard color slide films,
without any need for color separation techniques. Note also that
for mine storage with controlled humidity, sealed packaging is
not only not required for films, but may actually be detrimental
(films degrade much more slowly in free air than when packaged in
such a way that degradation products cannot escape).
The Granite Mountain Records Vault (near Salt Lake City, Utah)
which is used by the LDS church for record storage, has been
mentioned on this thread. I do not have information as to
exactly what things are accepted for storage there, but it's
worth finding out. This vault maintains 55 F and 30-40% RH,
which should be good for a stretch factor of at least four from
our baseline conditions. This also would be quite adequate for
storing color slide and (of course) color microfilm, though not
good enough for color negatives or prints (unless you are a cryo-
optimist).
Finally, time capsules as described by Mike Darwin are an
option, but only after some testing to ensure that proper
relative humidity for the planned storage temperature is
maintained after sealing. Welded metal time capsules are the
only viable option for ground burial, and for obvious reasons,
high and dry ground with temperatures below 65 F should be
chosen. At present, I believe that Ilford Ilfochrome for color
photos, and black-and-white microfilm for text, are the only
viable media for reasonably-sized time capsules (unless one
counts DNA for storing genetic information). Choice of these
media and avoidance of magnetic media also allows for marking of
the buried time capsule for future searchers with a strong
permanent magnet, ala the buried lunar monolith in _2001, A Space
Odyssey_.
Refrigerators
Finally, we come to refrigerators. Refrigerators are not
needed for storage of black-and-white or color microfilm or color
slide film, but they are necessary for the storage of color
negatives and many color prints, if for more than a couple of
decades. It is up to the individual to decide, however, whether
a refrigerator is warranted for storing color negatives, or
whether duplication to more permanent color positive film is in
order. Refrigerators are needed for magnetic media, for which
there is presently no good storage alternative (diskettes and
video and audiotapes), and the unused space in such refrigerators
may come to be used for photographic media as well. The factor
of 16 in decay-delay for film at the easily reached temperature
of 39 F. in a modern refrigerator, is enough to allow even
unstable color print films to be stored for more than a century
without problem.
The above assumes that somebody, even after you are gone, has
the time and money to house and replace the refrigerator-- not a
great assumption. At least while you are animate, however, a
personal archive refrigerator is helpful in many ways. For one,
your refrigerator also doubles as a good fire safe in this
regard, provided you have some way to latch or chain the door
(all modern refrigerators have only a burnable rubber magnetic
seal for safety reasons, so you'll have to add a fastener if you
want a dedicated refrigerator that acts as a fire-safe, by not
coming open significantly in a fire).
Remember, standard plastic fire-safe boxes for papers will
NOT protect negatives-- photographic materials require much more
expensive fire safes that cost as much as a refrigerator does
anyway, but which do not refrigerate! My advice is to take
advantage of the engineering done for you in the modern re-
frigerator, and store negatives in hermetic envelopes within a
standard plastic document fire-safe box, inside a dedicated door-
secured refrigerator. This gives you cold plus adequate fire
protection.
Choice of a refrigerator must be made with some care. You
want a frost-free unit in which the only cooling coils are in the
freezer section, and these not exposed. In such refrigerators
the cold and humid air from the freezer is used to cool the
refrigerator section, becoming in the process much drier in RH as
it warms. This very dry refrigerator air is dehydrating for food
(this is annoying for kitchen uses) but exactly what is wanted
for film. Examples of such refrigerators are the Maytag-made
units sold by Sears. Do NOT store media in the freezer section
of such refrigerators, which undergoes rapid thermal cycling in
the process of keeping the frost off food (there is, by contrast,
very little thermal or pressure cycling in the *refrigerator*
section of frost-frees, although humidity does briefly go up
during the thaw cycle). Also, remember that archive refrigerat-
ors should be dedicated units-- do not store food (which contains
oils and pollutants which can harm media) in such refrigerators.
Always check the RH of such units with standard hygrometers
(available from University Products, see below)
FINAL RECOMMENDATIONS
1) Go through your photos. Separate high-risk color negatives
made before 1976-1977 (when the E-6 process came in) from those
made later. Sort prints into faded and discolored prints vs
those that still look good. Get all prints into polypropylene
pocket albums, and out of PVC plastic or sticky paper albums.
Get all negatives into polypropylene archive sleeves.
2) Discolored film and prints must be duplicated NOW before they
deteriorate further. Have old or discolored negatives or prints
or slides duplicated onto Ektachrome slide duplication film (this
is fine grained slow film suitable for duplication-- Ektachrome
Slide Duplicating Film 5071). You must use Ektachrome for
duplication because no comparable fine-grained slow Kodachrome
film is available for this purpose. Duplicate even your
Kodachromes to Ektachrome 5071 for off-site backup. Finally,
pick out your very most important or representative photos and
consider having them duplicated to Ilfochrome color microfilm for
the ultimate dark color-stable archive backup.
3) At some point, you should have 3 copies of every photo on
either color slide film, or Ilfochrome color microfilm. Don't
waste low temperature on microfilm or Ilfochromes-- these are
excellent films for storage at home in a closet, in a bank safety
deposit box, or in your paper file at your cryonics facility.
Primary Kodachromes, and Ektachrome 5071 slide duplicates,
however, should probably be stored at slightly below room
temperature in controlled conditions. These are good choices
for mine storage. Do not store color negatives in mines or at
home-- these need better care. Store everything in polypropylene
inside Tyvek envelopes.
4) Consider buying a proper frost-free dedicated archival refri-
gerator for magnetic media, and use the unused space inside to
store old original color negatives (or prints) in hermetic foil
envelopes (or three layers of aluminum foil sealed with
electrical tape). Remember, you must get a refrigerator with a
freezer section, but you cannot put anything IN this section
except possibly ice-cubes and your spare household batteries.
5) Document! Most of these photos won't mean a thing to other
people, and many might not mean much to you if you wake up
without parts of your memory. You need to caption them NOW.
A handy way to do this is to assign each roll of film a 3 letter
code AAA to ZZZ, with 3^26 possible combinations (more than
you're likely to shoot in a lifetime). Start with BAA to give
you some slack before the beginning, and try to assign rolls in
rough chronological order. Label each set of film strips or
slides from a roll with the number (space-pen or pencil writing
on acid-free paper inserted into the polypropylene sleeve works
fine).
The frames in each roll are numbered 1-36, so each photo has a
unique identifying number, such as BAB-13 (no need to number each
frame). Start a master computer file with the number of each
roll and date (as well as you can fix it), and a small caption
for each photo (What are we seeing and who; Why did you take the
picture; Are there emotions associated with it?). When you get
done with this monster task, you can simply print this entire
master list out, microfilm it, get many copies made, and include
one with each film packet you make up, and several at every site
where you store film. Scatter them all over, and include several
in your cryonics files.
6) Think about what photos you want to go into LN2 with you, and
make a list. These will go in with your microfilmed diary, and
perhaps a few bits of magnetic tape. Don't waste time putting
Ilfochromes into LN2-- these are so stable that they should be
off-site in someplace where they might survive even at room temp,
neglected, along with you (photos for LN2 should be Ektachromes).
As Mike Darwin has pointed out, there are several scenarios in
which cryonicists may survive only as solid-packed in braincases
in LN2, with no room for ANYTHING else. So don't figure the
copies that go into LN2 with you are going to survive if you
will-- they may not.
7) Start routinely shooting Kodachrome slides, or at least
Ektachromes, and routinely have a couple of Ektachrome 5071
duplicate sets made (without mounting) for off-site backup. When
you shoot color print film and get it printed on Kodak paper, you
just leave yourself with a problem that will haunt you in 10-20
years. If you loose your negatives and put your prints in gummy
albums and otherwise don't pay attention, it will haunt you even
soon than that.
8) Get moving on the project-- for if you don't do it, it
probably won't get done. If there's one thing a lifetime has
taught me is that things get lost and go to hell naturally, quite
on their own. Even if cryonics works perfectly, a great many
cryonauts are going to come out the other end with no personal
information at all besides what is in the public domain
(newspapers, library material) and what is stored in their own
brains and those other resuscitees. Think about how much you
know of the life of your own great-great-grandfather. How many
things exist in your family that belonged to him? What, none?
That's the devastation of entropy that we all face. The living
have their own problems which have little to do with keeping the
memories of "dead" people fresh. So don't rely on them more than
you have to.
Steve Harris
As an afternote, for serious archivists I should recommend the
follow company:
University Products, Inc.
517 Main Street (P.O. Box 101)
Holyoke, MA 01041-0101
1-800-762-1165
FAX 1-800-532-9281
These guys have the PACKAGING for that film and those
flopticals. They have archival quality acid-free papers and
storage materials for photographic materials, tapes, papers,
etc., besides a wealth of specialty products for keeping things
safe from the ravages of time like UV filters, photo-safe
adhesives, Tyvek products (Tyvek is that incredibly tough paper-
like plastic stuff 5.25" floppy sleeves were made of; very inert
for archiving anything), aluminized airtight heat-sealable
plastic pouches, hygrometers, and so forth.
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