Problem of oxidation on B&W prints

 

I am currently in my final year at the ENS Louis Lumiere (one of two french Photography schools) and am conducting research into a process of silver oxidation, the causes of which remain unexplained. This process affects black and white prints(RC or FB) notably on warm tone papers. The silver oxidation is characterized by a yellowing and sometimes silver mirroring along the lines of contrast between high and low lighting and can appear partially or cover the whole image.

It seems to depend on the storage and viewing conditions. It is surprising because of the speed at which it develops, becoming apparent in only a few weeks or a few months in some cases, and because it usually appears on prints which have been treated with the utmost care.

 

If you have ever encountered this problem, I would be very grateful if you could answer the following questions which would help me in my research. Thank you in advance.

 

QUESTIONNAIRE :

 

Which paper did you use ?

 

Make / Type :

 

RC ou FB :

 

Which fixer did you use ?

 

Make / Type :

 

Dilution :

 

Fixing time :

 

Number of baths :

 

How did you wash your prints ?

 

Kind of water ( tap, treated, filtered, �) :

 

Characteristics of the water :

 

Temperature ( in C ):

 

Washing time :

 

Did you use a wash aid ? Yes / No

 

If yes,

Dilution :

 

Make / Type:

( He1-hyposulphite elimination- / washing accelerator / stabiliser)

 

Did you use a washer ? Yes / No

 

If yes,

Vertical ? Yes / No

 

Make / Type :

 

Did you use a toner ? Yes / No

 

Kind of toner :

 

How did you dry your prints ?

 

In the open air : Yes / No

 

If yes, how :

 

using blotting paper : Yes / No

 

If yes, type :

 

Did you use a cooler ? Yes / No

 

If yes, Name / make :

 

How did you flatten your prints ?

 

(In the) cold (state) : Yes / No

 

If yes,

Between pasteboards : Yes / No

 

If yes, type :

 

( In the) hot (state) : Yes / No

 

If yes,

Name / Make of the press :

 

Temperature ( in C) :

 

Kind of pasteboards :

 

Did you exhibit your prints ? Yes / No

 

If yes,

How long did you exhibit them :

 

Description of the place where they were exhibited

 

Geographic situation :

Time of the year :

Air conditioning :

Illumination :

 

Type of frame ( wood, aluminium�) :

 

Were the pictures framed by a professional ?

 

If yes,could you give me his/her name, address and phone number :

 

 

If no,

Type of pasteboard

 

Name / Make :

 

Type of adhesive ( Name / Make)

 

Adhesive tape : Yes / No

 

Corners : Yes / No

 

Spray glue : Yes / No

 

Heat sealed film : Yes / No

 

If no, what were the conditions of storage ?

 

Length of storage :

 

Description of the place where your prints were storage :

 

In the dark ? Yes / No

 

Type of storage ( plastic envelope,

Permanent paper, crystal, natural pasteboard or

Special archive cardboard, picture albums �) :

 

Name / Make :

 

Were your prints in direct contact with each other ? Yes / No

 

Environment of the prints :

 

Illumination ( fluorescence, tungsten, natural light�) :

 

Room Temperature (in C) :

 

Relative humidity :

 

observation of the phenomenon :

 

colouring of the oxidation :

 

type of oxidation(partial or total, in the high lights,low

density�) :

 

How long did it take to you to become aware of the phenomenon ?

 

Remarks :

 

 

 

 

<p>

 

 

 

Personally, I have never encountered that problem, but as I am

preparing an article about the stability of (not only) RC papers for

an online magazine, I have seen some examples of damaged prints. (I am

indebted to three gentlemen of Agfa who took the time to present the

examples to me, and to explain the cures.) So I can give you a few

qualitative hints and keep my promise (given in an earlier posting)

to disseminate some of the info I collected.

 

<p>

 

1) You are right in that working to exacting archival standards will

not protect you from silver oxidation. Silver, albeit being regarded

as a "noble" metal, silver is actually quite reactive, and it doesn't

take much to oxidise the silver image.

 

<p>

 

2) Damage to prints can become visible in as little as a month.(I saw

examples of prints ruined in four weeks by hanging them in a barber's

shop, i.e. in an atmosphere with a lot of formaldehyde and other

solvents - boy, I'am glad I haven't got to work there!)

 

<p>

 

3) Warm-tone papers having a silver image consisting of finer grains,

thus having more effective surface for the oxidants to attack, seem

more vulnerable, but the difference is small.

 

<p>

 

4) The process is accelerated by light, which means that storing your

prints in the dark will make them a bit more stable, but eventually,

if the air is bad, this will not fully cure the problem.

 

<p>

 

5) Partial toning in selenium (such as the toning for a better D_max

in highly diluted selenium toner) will not protect the image

sufficiently. If you tone to get archivally stable images, tone until

there is a clear change in image tone, i.e. in strong selenium and/or

for longer toning times.

 

<p>

 

6) For partial toning in gold toner the same holds.

 

<p>

 

7) Sulfiding toners (such as the bleach-and-redevelopment toners with

ferri/KBr bleach and sodium sulfide toner or the polysulfide variant,

like Agfa Viradon) do protect the image. It is then as stable as it

can get (but brown).

 

<p>

 

8) There is a product by Agfa, Sistan, which protects the image by

precipitating any soluble (= oxidized) silver ion in the emulsion in

the form of an insoluble salt. Sistan is basically a potassium

thiocyanate solution plus a wetting agent, which is used as the final

bath (thus no washing after the sistan treatment). It is said to be

compatible with other toning methods (such as partial selenium

toning), and also with spotting. There is a more or less equivalent

product by Fuji, which is called AG Guard, which, however, appears to

be offered on the Japanese market only.

 

<p>

 

9) No manufacturer of photo paper will give you any guarantee that

images made on his paper will last for whatever period, even given

proper processing. This is not because the manufacturers are bad guys,

it's because they can't take any responsibility for the air quality at

the place where the image is hung.

 

<p>

 

10) RC paper does NOT appear to be inherently worse than FB paper. The

problems reported by Ctein in the nineties are said to have been

solved by the addition of anti-oxidants to the base during major

revisions of the papers in the late nineties. (I am quoting this from

one manufacturer.)

 

<p>

 

Thomas Wollstein

I have always presumed that the dark prints with detailess shadows,

of the old timers (particularly Strand, Stieglitz, and others of the

early 20th Century) that one sees in museums is due to oxidation of

the silver. That they were probably not printed so dingy. True?

So far as I know, Agfa hasn't provided anyone with any substantiating documentation that Sistan works as claimed. It's agreed that it _should_ work, but apparently no proof is forthcoming.

I encounteered browning problem with Ilford multigrade RC paper as well as Agfa multicontrast RC paper. Kodak developer and Kodak fixer. Prints kept in album are ok, only the prints in glass frames turned brown in about 6 months time.

However after treatment with Kodak Selenium toner, all prints seems to be stable.

I do custom phogographic framing as well as my own photography. I

specialize in photography with the framing. For the past 5 years

Bainbridge has had available their line of Artcare mat & mounting

board, both in 100% rag as well as pulp boards of various types. This

has some kind of 'micropore chamber' that actively traps pollutants

that will effect the print. In accelerated againg tests in

atmospheres containing sulfur dioxides and other normal pollutants,

prints matted & mounted with these boards perform much better than

the normal 100% rag, acid free, buffered boards.

Take a look at the current issue of View Camera magazine where

Michael A. Smith has an article on the matboard. Dramatic differences

are shown. This is NOT light fading as the testing is done in the

dark. It is the result of aerial pollution and (possibly) outgassing

from the prints and/or framing as well.

At any rate, I have been using this board for 5 years now & wouldn't

want anything else, especially after seeing test results from a

number of different sources.

It may be one option in trying to protect prints as they are shown.

I never cease to be amazed at the quality of responses on this forum,

in this case to a question that properly belongs on the Printing &

Finishing forum (where it was also posted).

 

<p>

 

I find that I am behind the times on this archival stuff. Where can I

find references regarding research about the archival effects of

toning? I believe John Hicks mentioned Nishimura--has he published a

book? It sounds as though, if I obtain the long-sought split tone

effect, I will need to use Agfa Sistan to stabilize the image. But

there is also a warning that Sistan has never been tested properly.

Maybe we could write to this Nishimura guy and ask if he has tested

it, or plans to test it (?).

 

<p>

 

I used to tone my Oriental Seagull prints in selenium until they

turned quite reddish-brown--particularly landscapes (one of those 15

year-old images has been hanging on my wall all this time, with no

apparent ill effects). On the one hand, I am gratified that my love

of a deeply-toned print has proven to be "the way to go," but I also

treasure the three-dimensionality that the split tone effect provides

and don't want to give it up as an aesthetic option.

 

<p>

 

And what about Wilhelm Research? They do all sorts of archival

testing, but I find nothing on their site about black and white

prints, except a warning against using RC papers. Do you suppose, if

a coalition of fine-art photographers wrote to them, they could be

induced to do some testing in this area?

Ctein did some testing of Sistan and reports in his book "Post

Exposure". The new version is out now with new information.

See below for some info; although it's about microfilm it's relevant. Note the date.

 

<p>

 

http://palimpsest.stanford.edu/byorg/abbey/an/an12/an12-5/an12-507.html

 

<p>

 

A month or two ago Doug Nishimura posted some new findings and recommendations on rec.photo.darkroom, both as just posts and some as Q&A with Richard Knoppow. A deja.news search would probably turn those up.

 

<p>

 

Wilhelm is apparently ignoring everything but printer papers, inks etc, most likely because that's where the money is.

Thanks John. I also found some interesting posts by Doug Nishimura

and Luis Nadeau at http://palimpsest.stanford.edu/byform/mailing-

lists/cdl/1993/author.html. I plan to write a brief article on

archival processing for my web site, and include information from

these sources, as well as what T. Wollstein has posted here about

Sistan. I found another post that referenced one of Robert Chapman's

columns in Creative Camera Techniques where he said he had been

trying to get some proof from Agfa as to Sistan's effectiveness, but

their responses had been insufficient.

Dear Ed,

 

<p>

 

I am the responsible product manager for all B&W chemicals at Agfa.

This includes SISTAN too. Unfortunately, I did not get any question

for some proof. Since I could not find Robert Chapman´s column I

cannot answer him. Please could you give me his address or of the

creative camera techniques magazine. I could not find it in the

internt.

Please contact me If you have questions regarding SISTAN. I try to

answer your questions or to help you as far as I can.

 

<p>

 

Kind regards

Wolfgang Holz

 

<p>

 

Agfa-Gevaert AG