X-Message-Number: 8213
From: (Steven B. Harris)
Newsgroups: sci.cryonics
Subject: Re: Storage of memory records
Date: 15 May 1997 06:12:43 GMT
Message-ID: <5le9gr$>
References: <5laji3$>
In <5laji3$> (Brent Allsop) writes:
>
>Cryonauts,
>
> It seems to me one of *THE* most important parts of preserving
>oneself is the preservation of memories. If I forget something it is
>as if part of me is "information theoretically" dead even if I'm still
>alive.
>
> Isn't preservation of records like diaries, letters,
>photographs, video... therefore, also important to preserve along with
>the brain? I've got an electronic archive of megabytes of e-mail and
>notes over the past 10 years that is a very large part of what I am.
>Loosing stuff like that would be nearly as bad as dying. I certainly
>can't remember every single e-mail I have ever sent or posted! Yet
>going back and reading it brings it all back.
>
> Anyway, has anyone looked into preservation of such stuff,
>along with bodies?
A Re-Post:
Dear CryoNet/Sci.Cryonics:
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
Photographs_, 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
archiving, 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
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 C-41 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. As a rule, color negative films and color print papers
are not very good for archival purposes, with expensive
exceptions to be noted below.
COLOR PRINT PAPER
Standard color 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 we want to archive 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
C-41 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 C-41 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, though not all
"one hour" stores have it). 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 regular 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 (available in
standard 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 at best does only E-6 one-hour slide
processing. 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 time 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 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
Kodachrome, 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 photo-
graphs 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
(relative 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
implications 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 (this is where
color images are stored on three black and white negatives, each
shot through a different filter). 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. 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 C-41 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 (available in any business supply store).
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 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) Stop shooting color print film (this will mean you'll have to
buy your film in other than grocery stores). Instead 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 lose 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 the living for
archival purposes 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 that no-tear mailing envelopes are made of,
and that 5.25" floppy sleeves were made of; it's very inert for
archiving anything), aluminized airtight heat-sealable plastic
pouches, hygrometers, and so forth.
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