From: sreenath on 8 Apr 2010 09:17
On Apr 8, 2:16 am, "Richard Knoppow" <dickb...(a)ix.netcom.com> wrote:
> "sreenath" <sreenat...(a)rocketmail.com> wrote in message
> > On Apr 6, 7:56 pm, "Richard Knoppow"
> > <dickb...(a)ix.netcom.com> wrote:
> >> "sreenath" <sreenat...(a)rocketmail.com> wrote in message
> >> > On Apr 5, 3:24 am, Toni Nikkanen <t...(a)morgoth.tuug.fi>
> >> > wrote:
> >> >> All of the above suggestions are great but being the
> >> >> lazy
> >> >> person I am,
> > Are there any alternatives to sodium sulfide for this test
> > and in
> > general for toning etc? I had about 500 grams of this
> > stuff, and it
> > absorbed water from air. I had to dispose it off.
> > I would like to avoid having this chemical around because
> > of the smell
> > and its ability to fog photo emulsions.
> > I use two bath fixer made from hypo for paper and have no
> > confusion
> > there as to degree of fixation.
> > When I fix fiber paper I also use a sulfite wash aid.
> > thanks,
> > Sreenath
> Kodak at one time recommended a 1:9 dilution of Kodak
> Rapid Selenium Toner. This has low odor. I don't know how
> easy it is to get now. Its used in the same way as the
> sulfide test except that it must be used on well washed
> films or prints since it may fail to stain if there is an
> excess of hypo in the emulsion.
> Ideally, neither test solution should leave any stain
> if the emulsion is fully fixed.
> Micheal Gudzinowicz posted some very complete
> explainations of how fixer works to this group several years
> ago. I think Google will still find them. They are worth
> reading because they will give you a better understanding of
> the limits on fixer capacity.
> Clearing time is a dangerous criteria to use in judging
> fixer capacity since partially exhaused fixer will "clear"
> film long after it has reached the point where it is no
> longer fixing out completely. Because there are no longer
> enough free thiosulfate ions to completely convert the
> halide to water soluble form mearly extending the fixing
> time will not compensate for this.
> I use Kodak Hypo Clearing Agent on both fiber paper and
> on film. Because the emulsion on RC paper is so thin it
> washes out to archival level very quickly without any
> special treatment. The use of KHCA on it may actually wash
> it too much.
> The older ideas about archival washing were based on the
> idea that NO thiosulfate whatsoever should remain in the
> emulsion, however, about 1960 T.H.James of Kodak Research
> Laboratories discovered that very small amounts of
> thiosulfate remaining in the emulsion would stabilize the
> image silver resulting is some resistance to oxidation. This
> was such heresy that James was reluctant to publishe his
> results until similar findings from Fuji's lab were
> published. The discovery caused Kodak to revise its washing
> recommendations. KHCA can wash down too far if its applied
> for too long and subsequent washing is carried on for too
> long. Current Kodak recommendations for KHCA and washing
> times in general take cognizance of this. Its interesting
> that a great many "drugstore photofinisher" snapshots have
> survived because they were fixed OK but not overwashed where
> materials given "archival" washing treatment but no toning
> have developed the symptoms of oxidation, i.e., silvering of
> the surface and staining of the image.
> Toning is still the best protection. The Image
> Permanence Institute currently recommends a polysulfide
> toner like Kodak Brown Toner for this because it gives
> uniform toning for partial toning. KRST, which used to be
> the standard method was found not to be effective for
> partial toning. It does, however, provide good protection if
> some change in image density or color can be tolerated. The
> recommendation is to use a dilution no weaker than 1:9 and
> for not less than 3 minutes at room temperature for prints
> and films.
> Richard Knoppow
> Los Angeles, CA, USA
How long will b/w prints last if fixed and washed properly, but not
I definitely can't get KRST here in India. I wanted to make my own
selenium toner, but gave up the idea after reading about the toxicity
of selenium compounds needed.
I can't get polysulfide either. I made my own soma years ago using
sodium sulfide and sulphur powder, and it worked very well.
Also, for landscape photos, I dont think sepia tone look good, so
would prefer Selenium toning, if only I can get it.
Traditional photo stuff has become unavailable here in India (Except
colour print film, and some slide film)
I had to buy b/w film from another city.
I used to read older posts by Michael Gudzinowicz, and they had loads
of very useful information. Miss his posts in rpd now.
From: Peter Irwin on 8 Apr 2010 11:25
sreenath <sreenathbh(a)rocketmail.com> wrote:
> How long will b/w prints last if fixed and washed properly, but not
I've seen a lot of early 20th century family photos which have survived
just fine with normal storage in photo albums and envelopes. There are
no guarantees (I think pollution can be a big variable), but there is
nothing particularly unlikely about an untoned black and white print
lasting a hundred years or more.
From: Richard Knoppow on 9 Apr 2010 02:36
"Peter Irwin" <pirwin(a)ktb.net> wrote in message
> sreenath <sreenathbh(a)rocketmail.com> wrote:
>> How long will b/w prints last if fixed and washed
>> properly, but not
> I've seen a lot of early 20th century family photos which
> have survived
> just fine with normal storage in photo albums and
> envelopes. There are
> no guarantees (I think pollution can be a big variable),
> but there is
> nothing particularly unlikely about an untoned black and
> white print
> lasting a hundred years or more.
That seems to be the case. If the films or prints are
fixed thoroughly they should be washed according to Kodak
recommendations. Since Kodak no longer makes B&W paper the
usual recommendation is to wash single weight fiber paper
for an hour and double weight for two hours in running
water. If a sulfite wash aid is used 20 minutes is enough
for single weight and half an hour for double weight. Since
the washing is a slow process longer wash times are OK
provided they are not extremely extended. The above is for
water at about 68F (20C), washing is faster in warmer water.
When a sulfite wash aid is used even quite cold water is
Washing is faster when a non-hardening fixing bath is
used since the usual white alum hardener acts as a mordant
for the thiosulfate when it is acid. By treating film or
paper with a mild alkali the mordanting is eliminated.
However, if the pH is much more than 7 (neutral) the
hardening is also eliminated. Kodak Hypo Clearing Agent is
buffered to neutral so that the hardening is preserved. The
alkali also serves to affect the electrical charges in the
gelatin so as to make it repel the thiosulfate ions where
when it is acid it attracts them.
Film washes out much faster than fiber paper because
the support does not absorb any hypo. For untreated film
fixed in a normal acid hardening fixer half an hour is
enough. If treated in KHCA five minutes is sufficient.
RC paper washes out in four minutes after normal acid
fixer even when no wash aid is used and wash aid is not
recommended by Kodak unless one is experiencing staining
problems when toning.
Polysulfide toner is the one recommended currently
because it provides protection to all densities even when
only partial toning is done. KRST tones the finer grains
found in the high density parts of the image before it tones
the coarser ones so that when highly diluted (1:19) KHCA is
used as formerly recommended, the low densites may not be
protected. If toning is carried out far enough it protects
I don't know of another toner that can be used for
partial toning and provide full protection against oxidation
and sulfiding. The standard for microfilm is gold toning. It
is quite effective and causes relatively little change in
tone or density on cold or neutral tone paper. Its drawback
is that its expensive. Gold will form fairly vivid blue
images on very warm tone paper but on neutral or cold tone
paper the color shift is small to none. Its useful where one
finds a paper a bit green.
Polysulfide toner is easy to make. Kodak gives a formula
as Kodak T-8. According to the IPI this is as effective as
Kodak Brown Toner for image protection. However, if you
can't obtain polysulfide that isn't very useful to you.
The theory about the small residue of thiosulfate is
that it causes a slight amount of surface sulfiding of the
silver crystals. Silver sulfide is very stable so once a
layer of sulfide forms it goes no further and is also
passive as far as oxidation is concerned. The problem is
that there is no definite information about wash times, etc.
Another anti-oxidation treatment involves the use of a
chemical like thiocyanate in highly diluted form. This is
what AGFA Sistan was. While Sistan was not as effective as
toning it does have the advantage of not causing any change
to the image color, density, or structure. The latter is of
little consequence in pictorial photography but can be
critical for microfilm.
FWIW, _any_ sulfiding toner will fully protect images if
carried out to completion, however all will change the image
color. KRST will provide full protection according to
Dr.Douglas Nishimura of IPI if used at a dilution of no
greater than 1:9 and for not less than 3 minutes at 68F.
Gold toners are very effective.
Other toners such as iron, copper, uranium, etc, form
imgages which are _more_ vulnerable than the original silver
image although they may produce attractive colors.
BTW, it has become much more difficult to obtain
photographic chemicals even here in the USA.
Los Angeles, CA, USA
From: Richard Knoppow on 9 Apr 2010 11:52
"Richard Knoppow" <dickburk(a)ix.netcom.com> wrote in message
> "Peter Irwin" <pirwin(a)ktb.net> wrote in message
>> sreenath <sreenathbh(a)rocketmail.com> wrote:
>>> How long will b/w prints last if fixed and washed
>>> properly, but not
>>> found in the high density parts of the image before it
> the coarser ones so that when highly diluted (1:19) KHCA
Mis-typed, should read KRST i.e., Kodak Rapid Selenium
Los Angeles, CA, USA