a mild bleach

Ugh... it seem the last batch of prints I did was on a somewhat too old
paper .... I've since cleaned up the whites be increasing the restrainer,
but I'm still left with a number of prints with slightly grey whites. Can
anyone recommend a mild bleach I could use to clean them up?
Thanks.

"Lew" wrote in message
...
Ugh... it seem the last batch of prints I did was on a
somewhat too old paper .... I've since cleaned up the
whites be increasing the restrainer, but I'm still left
with a number of prints with slightly grey whites. Can
anyone recommend a mild bleach I could use to clean them
up?
Thanks.
I aggee with the fellow who suggested checking you
safelight. However. It is possible to clear highlights with
a mild Farmer's Reducer used with mixed bleach and fixer.
This tends to clear low density areas faster than higher
densities. When used separately the reducer is more even in
action but you want to clear the highlights here with as
little effect as possible on the mid-tones and shadows.
Farmer's used to be available in packaged form from
Kodak and may still be from some other suppliers such as
Freestyle Photo. Its easy to make, the formula follows.
Potassium ferricyanide is relatively safe. The cyanide part
is very strongly bound and requires high heat or strong acid
to release cyanide gas. It may be considered a hazardous
material which may make it hard to obtain.

Kodak R4a

Stock Solution A
Potassium ferricyanide 37.5 grams
Water to Make 500.0 ml

Stock Solution B
Sodium thiosulfate (crystalline) 480.0 grams
Water to make 2.0 liters

To use take Stock Solution A 30.0 ml and Stock Solution B
120.0 ml Add water to make 1.0 liter. Pour the mixture
immediately over the negative. Watch closely. When it has
been reduced sufficiently wash thoroughly.
I suggest re-fixing and re-washing after reduction to
insure that there are not halides left in the emulsion which
can eventually cause staining or fading.

The above is given for negatives, which require a
stronger reducer than prints. You can dilute the reducer to
make it slower and more suitable for prings. You can also
"paint" the surface where you want to have reduction.

There are other reducers but their ingredients may be
more difficult to obtain. A good reducer for spotting is
iodine in solution. This is a very powerful reducer although
it can be high diluted. Since it converts the silver to
silver iodide, which is difficult to fix out the prints
should be treated in a film strength "rapid" fixer (ammonium
thiosulfate) after reduction.
A very mild reducer, one suggested mostly for removing
dichroic fog, which is a deposit of very finely devided
silver on the surface of a print or negative is a mixture of
film strength _acid_ rapid fixer with about 15 grams per
liter of citric acid added. This may suffice to clear
slightly veiled highlights. Film or prints so treates should
be re-fixed and washed.


--
--
Richard Knoppow
Los Angeles, CA, USA

.... this is definitely fog & old age. As I originally posted, other papers
process just fine & the problem for this paper is cleared up by adding
restrainer. Do you have any experience cleaning up highlights by bleaching?
..
"Peter" wrote in message
...
On Feb 16, 7:50 pm, "Lew" wrote:
Ugh... it seem the last batch of prints I did was on a somewhat too old
paper .... I've since cleaned up the whites be increasing the restrainer,
but I'm still left with a number of prints with slightly grey whites. Can
anyone recommend a mild bleach I could use to clean them up?
Thanks.

Did you check your safelight?

Sodium thiosulfate (crystalline)
Is this the same as Pentahydrate?

"Richard Knoppow" wrote in message
m...

"Lew" wrote in message
...
Ugh... it seem the last batch of prints I did was on a somewhat too old
paper .... I've since cleaned up the whites be increasing the restrainer,
but I'm still left with a number of prints with slightly grey whites. Can
anyone recommend a mild bleach I could use to clean them up?
Thanks.
I aggee with the fellow who suggested checking you safelight. However.
It is possible to clear highlights with a mild Farmer's Reducer used with
mixed bleach and fixer. This tends to clear low density areas faster than
higher densities. When used separately the reducer is more even in action
but you want to clear the highlights here with as little effect as
possible on the mid-tones and shadows.
Farmer's used to be available in packaged form from Kodak and may
still be from some other suppliers such as Freestyle Photo. Its easy to
make, the formula follows. Potassium ferricyanide is relatively safe. The
cyanide part is very strongly bound and requires high heat or strong acid
to release cyanide gas. It may be considered a hazardous material which
may make it hard to obtain.

Kodak R4a

Stock Solution A
Potassium ferricyanide 37.5 grams
Water to Make 500.0 ml

Stock Solution B
Sodium thiosulfate (crystalline) 480.0 grams
Water to make 2.0 liters

To use take Stock Solution A 30.0 ml and Stock Solution B 120.0 ml Add
water to make 1.0 liter. Pour the mixture immediately over the negative.
Watch closely. When it has been reduced sufficiently wash thoroughly.
I suggest re-fixing and re-washing after reduction to insure that there
are not halides left in the emulsion which can eventually cause staining
or fading.

The above is given for negatives, which require a stronger reducer than
prints. You can dilute the reducer to make it slower and more suitable for
prings. You can also "paint" the surface where you want to have reduction.

There are other reducers but their ingredients may be more difficult
to obtain. A good reducer for spotting is iodine in solution. This is a
very powerful reducer although it can be high diluted. Since it converts
the silver to silver iodide, which is difficult to fix out the prints
should be treated in a film strength "rapid" fixer (ammonium thiosulfate)
after reduction.
A very mild reducer, one suggested mostly for removing dichroic fog,
which is a deposit of very finely devided silver on the surface of a print
or negative is a mixture of film strength _acid_ rapid fixer with about 15
grams per liter of citric acid added. This may suffice to clear slightly
veiled highlights. Film or prints so treates should be re-fixed and
washed.


--
--
Richard Knoppow
Los Angeles, CA, USA

Lew wrote:
Ugh... it seem the last batch of prints I did was on a somewhat too old
paper .... I've since cleaned up the whites be increasing the restrainer,
but I'm still left with a number of prints with slightly grey whites. Can
anyone recommend a mild bleach I could use to clean them up?
Thanks.

Ansel Adams gives the following bleach for prints to clear the highlights. I
infer his use of this process was not to save old paper, but to arrange a
little more detail in the highlights.

Solution A

Water (room temperature) 300 ml
Potassium ferricyanide 62.5 gm
Potassium metabisulfite 4.2 gm
Water to make 500 ml

Solution B

Water (room temperature) 600 ml
Ammonium thiocyanate 330 gm
Potassium bromide 30 gm
Water to make 1 l

Mix 1 part of a, 2 parts of B and 10 to 15 parts of water. Immerse the dry
print face up with vigogous agitation for 5 to 10 seconds. Place immediately
in water and agitate until the bleaching solution has been removed from the
surface of the print. Examine the print , and return it if necessary to the
bleaching bath (advised only for a few seconds). If the print is wet
initially, or if the solution is too dilute, the middle and the lower tones
may respond to the action of the bleach, thereby weaking the print values in
general.


I advise being very careful with this or it will get away from you.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ PGP-Key: 9A2FC99A Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 07:55:01 up 26 days, 23:46, 3 users, load average: 4.27, 4.26, 4.14

Thanks, I've lost track of my Adam's books over the years.

"Jean-David Beyer" wrote in message
...
Lew wrote:
Ugh... it seem the last batch of prints I did was on a somewhat too old
paper .... I've since cleaned up the whites be increasing the restrainer,
but I'm still left with a number of prints with slightly grey whites. Can
anyone recommend a mild bleach I could use to clean them up?
Thanks.
Ansel Adams gives the following bleach for prints to clear the highlights.
I infer his use of this process was not to save old paper, but to arrange
a little more detail in the highlights.

Solution A

Water (room temperature) 300 ml
Potassium ferricyanide 62.5 gm
Potassium metabisulfite 4.2 gm
Water to make 500 ml

Solution B

Water (room temperature) 600 ml
Ammonium thiocyanate 330 gm
Potassium bromide 30 gm
Water to make 1 l

Mix 1 part of a, 2 parts of B and 10 to 15 parts of water. Immerse the dry
print face up with vigogous agitation for 5 to 10 seconds. Place
immediately in water and agitate until the bleaching solution has been
removed from the surface of the print. Examine the print , and return it
if necessary to the bleaching bath (advised only for a few seconds). If
the print is wet initially, or if the solution is too dilute, the middle
and the lower tones may respond to the action of the bleach, thereby
weaking the print values in general.


I advise being very careful with this or it will get away from you.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ PGP-Key: 9A2FC99A Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 07:55:01 up 26 days, 23:46, 3 users, load average: 4.27, 4.26, 4.14

"Lew" wrote in message
...
Sodium thiosulfate (crystalline)
Is this the same as Pentahydrate?

Yes. Most of the older formulae calling for sodium
thiosulfate specify the crystalline form. Modern packaged
fixing baths, such as Kodak fixer, are the anhydrous form.
The conversion factor is:
Where crystalline is specified use 0.64x of the anhydrous
form.
Where anhydrous is specified use 1.57X the crystalline form.
These are rounded off but sufficiently accurate for
photographic work.


--

--
Richard Knoppow
Los Angeles
WB6KBL