Developer does not remove the sensitizing dye that
results in the pink or magenta stain on T-Max film. The
stain is due to a dye which is persistent and is bound to
the gelatin and to silver in the gelatin. If the film is not
completely fixed the dye will remain because the complexes
it binds to remain.
  Films like T-Max and Tri-X which have a large amount of
Silver iodide in them are slow to fix. The iodide acts as a
restrainer on the fixing. Rapid (ammonium thiosulfate) fixer
is less affected by the soluble iodide so it continues to
fix at a faster rate even after accumulating iodide. Using
rapid fixer is a good practice for these slow to fix films.
  A two bath fixing regieme helps to overcome both the
accumulation of iodide and also the accumulation of
thiosulfate ions which are complexed with fixed out silver
halide. It takes a lot of free thiosulfate to produce
complete fixing and the capacity of a single bath, even of
rapid fixer, is quite limited. Because most of the silver
and most of the iodide accumulates in the first bath of a
two bath syetem the second bath is left in a condition where
it fixes at full rate and has enough free thiosulfate to
fully complex any remaining halide. This also tends to
reduce the amount of sensitizing dye bound to the emulsion.
The use of a sulfite wash aid further releases bound
silver-thiosulfate complexes and also the dye bound to them.
One minute is probably not long enough, probably two minutes
is about right.
  Check the clearing time of the film you are going to fix
in the type of fixer you are going to use. The fixing time
can be established by this. Soak a sample of the film in
plain water for a few minutes because the fixing rate of
wetted film is different than dry film. Then fix until the
film is visually clear (not turbid from halide), it may
still have stain at this point. Fixing should be at least
twice this time. If a two bath system is used fix in the
first bath for the clearing time and in the second bath for
an equal time.
 Film can be tested for excessive retained silver and
silver complexes by a simple test using either a 2% solution
of Sodium Sulfide (not sulfite) or a 1:9 dilution of Kodak
Rapid Selenium Toner. The toner test has the advantage of
being stable for a long time and free of the rotten egg odor
of the sulfide. However, it fails if there is much hypo in
the material so it can be used only on well washed film or
paper. Place a drop or two of the test on a clear area of
the film or paper. The film or paper should be wet but the
surface should be blotted or squeegeed off. leave the test
solution in place for about 2 minutes and rinse it off. It
should leave no stain at all. Place film against a white
surface to make any stain more visible. If there is any
yellow or brown stain it indicates that fixing is not
complete.
 I have no idea why T-Max 100 should be harder to fix than
T-Max 400 but perhaps it is.

 This isn't quite how it works. First, emulsion hardness is
a measure of the amount it swells. Swelling can be caused by
heat or by being more alkaline or more acid than the
isoelectric point of the gelatin. Gelatin is amphoretic,
that is, it is neither acid or alkaline but has some of the
characteristics of both. Gelatin has a sort of preferred pH
called the isoelecric point. The isoelectric point is
determined by the way the gelatin is processed. Most
photographic gelatin is acid processed and has an
isoelectric point slightly on the acid side of neutral. When
gelatin is immersed in a bath it takes on the pH of that
bath. At the isoelectric point the net electric charges in
the gelatin are neutral, on either side there is a net
charge. This is important because some ions are held to the
gelatin by their relative charges, as in like charges repel,
opposite charges attract. When gelatin is on the acid side
of its isoelectric point it tends to bind thiosulfate and
silver complexes. By treating the emulsion in a neutral or
alkaline bath the pH is moved above on the alkaline side)
the isoelectric point and the charges then tend to repel the
adsorbed ions, accelerating washing. One purpose of a
sulfite wash aid is to provide this pH adjustment. Any
alkali will provide this effect. In the past several
materials have been recommended: Agfa recommends a 2%
solution of sodium carbonate, in the past Kodak recommended
a 2% solution of Ammonium carbonate (because the Ammonium
came out faster in washing). One can also use Sodium
Metaborate (Kodalk), or even Borax.
  Another reason for using an alkaline bath before washing
is to eliminate the mordanting effect of white alum hardener
in hardening fixing baths. The alum has a specific binding
effect on thiosulfate and silver complexes. This binding
takes place over a range of pH from acid to about neutra. By
making the gelatin alkaline the binding effect is eliminated
resulting is a substantial increase in washing rate.
However, at the pH of the above treatments the cross linking
that results in hardening is destroyed.
  Kodak Hypo Clearing Agent employs Sodium sulfite. The
sulifte acts as an alkali but it also has another function.
Sulfite turns out to be an effective ion exchanger for
thiosulfate and thiosulfate-silver complexes. The sulfite
actually displaces these ions but is not bound the either
the gelatin or image silver itself.
  KHCA is buffered to neutral pH. Kodak gives two reasons
for this: First, at neural pH the emulsion is above its
isoelectric point so there is no longer binding by charge,
it is also above the pH at which alum hardener binds ions.
However, at neutral the hardening caused by the hardener is
substantially intact. Another reason is that at neutral pH
the emulsion is close to its isoelectric point, which is
also the point of _minimum_ swelling. At this point the
diffusion path which must be taken by ions leaving the
emulsion in the wash is also minimised.
 I should point out that gelatin hardness has little if any
effect on diffusion rate. Swelling can, but as indicated,
diffusion is greatest when swelling is minimum. If you think
of the emulsion as a sponge this will make sense. A
compacted sponge will absorb more water than a swelled one.
Something similar happens with the gelatin of the emulsion.
  T-Max and some other films, including Tri-X are slow to
fix partly because they contain a lot of silver iodide.
Three forms of silver halide are used in emulsions: Silver
chloride, silver Bromide, and Silver Iodide. Silver chloride
is very slow and is found mostly as a component in printing
paper. Silver bromide is faster and found in both paper and
as the basic form of silver halide in film. In addition most
films have a substantial amount of Silver Iodide, which is
important in producing film speed. These three are, of
course, in soluble in water in the form they take in the
film. They are made soluble by the fixing bath. The fastest
to fix out is chloride, the next fastest is bromide, the
slowest is iodide. Iodide is very slow to fix compared to
the others. In addition the free iodide ions act as a
restrainer to the fixing bath slowing it down even more.
Iodide has a much greater restraining effect on Sodium
Thiosulfate fixer than on Ammonium thiosulfate (rapid)
fixer. This is one reason that rapid fixers are recommended
for films of all types but especially for high iodide films
shuch as T-Max, Delta, and Tri-X, which tend to fix out very
slowly in sodium fixing baths. While the main limit to fixer
capacity is the amount of free thiosulfate ions, in other
words by the amount of thiosulfate bound up with dissolved
silver, the amount of dissolved iodide is also important.
Since it has less effect on ammonium thiosulfate fixer than
on sodium the relative capacity of the rapid fixer is
greater. It takes a lot of free thiosulfate to convert the
halide into fully soluble form, three thiosulfate ions for
each halide ion.
  Residual dye: T-Max and Delta films have a sensitizing
dye which seems to be persistent. Sensitizing dyes are added
to the emulsion mostly to sensitise it to color. The basic
emulsion is sensitive to near UV, blue, and blue green (for
Iodide). To get sensitivity in the green and red regions of
the spectrum a dye or combination of dyes are added. These
dyes are usually removed or decolorized in the deloper but
it appears that the dyes used in T-Max are not, or else are
bound in some way by somthing else in the emulsion. The dye
is definitely not a delibrate addition to indicate the state
of fixing. Likely, the dye is bound by the same mechanisms
that bind thiosulfate and complexes, namely the electric
charges in the emulsion. It appears that any treatment which
eliminates this binding will also free the residual dye.
Certainly KHCA causes it to be released.
  Note that the washing time for film recommended after
using a standard hardening fixing bath is half an hour at
around 68F. After using KHCA a five minute wash is enough.
This is indictative of the effectiveness of both the
modification of the pH and the ion exchange efffect.
  Residual silver halide:  It is possible to test the level
of residual silver halide and silver complexes produced by
the fixer in film or paper. The standard test is a 2%
solution of Sodium Sulfide (not sulfite) for well washed
film or paper a 1:9 dilution of Kodak Rapid Selenium Toner
can be used in place of the sulfide. It is more stable and
does not have the rotten egg odor of the sulfide. However,
it fails where there is an excess of hypo in the emulsion.
 To use either solution place a couple of drops in a clear
area of the film or paper. Allow to stand for about 2 to 3
minutes. The rinse off. There should be no visible stain.
Film should be held against a white surface to make any
stain more visible. If there is any residual halide or
reaction products they will cause a yellow or brown stain.
This is really the ultimate test of fixing.

DON'T USE ANYTHING BUT RAPID FIXER!

  If you are washing in a multiple roll tank, like the old
tall Nikor tanks, stick a hose down the center of the reels
and feed the water from that. The tank makes a very
efficient washer that way. Water flowing onto the top of the
tank will not usually get down to the bottom. If you can't
rig a hose fitting fix a section of hose to the bottom of a
funnel and run the faucet into that.

...

...

may3005 from Lloyd Erlick,

I can't prove this, and I'm not exactly an
authority on color either, but I think the
color that comes out of TMY (T-Max 400)
during processing has not been consistent
over the years. I think Kodak has made
changes in that regard over time, and since
the film is ten years old it may have
different characteristics.

In a slightly different vein, I have stored
exposed rolls of TMY for up to three years
before processing. I have never found any
difference from promptly developed film in
the resulting negatives when I make prints
from them.

Also, I have been using exactly the fixing
regimen you mention (sodium thiosulfate, two
bath fixer, six minutes in each bath -- I
agitate constantly in the fix) for years. I
also see no residual dye stain right from the
fixer, unless I have been extremely sloppy
and over-used the fixer. I think a healthy
fixer is very important.

regards,
--le

I have found the temperature of the HCA (HEICO, in my case)
and wash water has a lot of influence on getting the pink
out.

At 75F the pink washes right out with no problem.  At 65F
and below (think Cleveland winters and the price of natural
gas) the pink stays in.