Pink stains on BW prints

[Marco B]

Hi,

I've probably been a bit sloppy today (well, actually, I know why, since I've been messing around with a brush to develop my prints), but a number of prints are now showing faint pinkish / reddish stains after washing. Initially, these were not visible, but gradually became visible during the washing cycle.

My fixer is OK (tested it), and I even made some new to see if it would clear out these stains, it didn't.

I have very occasionally seen this happening before, and if I remember it correctly, I heard someone saying this might be caused by fixer coming into contact with the paper *before* entering the developer bath, e.g. by contaminated hands.

- Is this true, or is there another cause for this? :confused:
- Whatever the cause, can someone also give some inside into the reaction / chemistry behind the development of these stains.

Last but not least:
- Are the prints in anyway salvageable, so can these stains be removed without ruining the print, or do I need to ditch them (more likely)?

Any info highly appreciated...

Marco

 

[Ole]

Allow me to sober up before I answer. In the meantime, try giving the prints a good soak in an acidic rapid fixer.

 

[FilmIs4Ever]

It's the Fixer

In the mean time, do not use that fixer. Pink or purple stains are the only caused by exhausted fixer to my knowledge, and that is a classic sign. Maybe your hypo test is bad. I tend to try to keep track of fixer exhaustion mathematically in terms of the square inchage of prints going through, so that you know exactly when the stuff has gone bad. Fixer is cheap, just don't use it.

Do you have a scanner? Post some scans for us to see of the marks so that I can tell you for certain, but from your description it sounds like an open-and-shut case of fixer exhaustion.

~KB

 

[Marco B]

Allow me to sober up before I answer. In the meantime, try giving the prints a good soak in an acidic rapid fixer.

Acidic fixer?? Aren't fixers always basic? Well, maybe not, but what kind or make of fixer are you suggesting. Most brands seem to be simply ammoniumthiosulphate, which is basic.

 

[ath]

Which paper did you use? Forte polywarmtone is known for pink residue when not properly fixed. Polywarmtone needs strong, fresh fixer.

 

[FilmIs4Ever]

Oh, one other thing that just dawned on me. If it is fresh fixer and you aren't following the fixing time (i.e. too SHORT), then this same thing would probably happen. Make sure you are fixing for the proper length of time (remember that if you are too much above or below 70 degrees F your times will need to be adjusted too).

~KB

 

[Marco B]

The paper is Ilford Warmtone FB. I do time and temperature my baths for control, everything seemed OK. Admittedly though, it's about time I clean up the developer bath. It has grey staining on the inside, and I used it as underground for my brushwork. Maybe that's part of the issue. Actually, what is the grey deposit? At first thought, one would expect no silver to be released in the developer, but it seems to. I've noticed once that a drop of fixer seems to dissolve the grey staining inside a developer bath.

I know there are specialized products for cleaning trays. Can anyone recommend something?

 

[Dave Miller]

Quote: "I know there are specialized products for cleaning trays. Can anyone recommend something?"

Soap, water, and elbow grease.

 

[Marco B]

Soap, water, and elbow grease.

Thanks Dave, saves a few bucks

 

[Neil Miller]

Marco - you aren't using an amidol based developer are you?
Regards,
Neil.

 

[Ole]

Acidic fixer?? Aren't fixers always basic? Well, maybe not, but what kind or make of fixer are you suggesting. Most brands seem to be simply ammoniumthiosulphate, which is basic.

Traditionally, fixers were always acidic.

"Most brands" are ammonium thiosulfate plus some othe chemicals like sulfite, bisulfite, and so on to improve keeping properties and ensure the specified pH.

Acidic rapid fixers (or any rapid fixer which has been acidified through the addition of a little acid) tend to bleach silver ever so slightly, which is precisely what will remove the pink cast in the highlights that you get when an inproperly fixed print has been exposed to light.

So what I suggested was not only a refix in new fixer, but a slight bleach as well.

 

[fschifano]

Quote: "I know there are specialized products for cleaning trays. Can anyone recommend something?"

Soap, water, and elbow grease.

Those stains are silver. Dave's elbow grease method will work sometimes, but it depends on the tray and you'll never get it all. There is an easier way that will not cost a fortune. Pour some bleach (potassium ferricyanide) into the tray and let it sit for a while. That will return the silver to a silver salt which can then be dissolved and carried away with some fixer.

 

[dancqu]

Polywarmtone needs strong, fresh fixer.

Fresh is the only way I use fixer; real fresh one-shot.
Small volumes of very dilute chemistry using a tray
rather than a tube make single tray processing
a snap. About 1:24. A use then dump. Forte's
paper is fixed in 3 minutes. Dan

 

[Photo Engineer]

Retained developing agent will gradually oxidize and cause a colored stain. The color depends on the developing agent(s) used.

Acid alone will not remove them. Actually a sulfite bath is best because sulfite reacts with oxidized developers and enables them to be washed out. Many people forget that this chemical is an aid to removal or prevention of retained developer stains.

PE

 

[dslater]

if you have a dedicated developer tray is the stain something you really need to worry about? At the local art school I have seen developer trays that were nearly black with stain.

 

[Vaughn]

I usually see the dreaded pink stain when students just toss their prints in the fixer and go print another one -- prints will sit there in the fix and where two prints are touching, there is little "fixing" going on.

We scrub our SS trays every time we replace the developer. Otherwise the silver gets on the prints when the prints rub on the bottom of the tray (black marks).

Vaughn

 

[dslater]

I usually see the dreaded pink stain when students just toss their prints in the fixer and go print another one -- prints will sit there in the fix and where two prints are touching, there is little "fixing" going on.

We scrub our SS trays every time we replace the developer. Otherwise the silver gets on the prints when the prints rub on the bottom of the tray (black marks).

Vaughn

But even with the scrubbing, don't the trays eventually get dis-colored with a stain that won't scrub off and doesn't get on the prints?

 

[dancqu]

Acidic rapid fixers (or any rapid fixer which has been acidified
through the addition of a little acid) tend to bleach silver ever
so slightly, which is precisely what will remove the pink cast in
the highlights that you get when an inproperly fixed print has
been exposed to light.

So what I suggested was not only a refix in new fixer,
but a slight bleach as well.

Very dilute Farmers Reducer may be a good cure. Odd the
hue is red-ish. In testing I've slightly to grossly under-fixed
a few papers and have been left with hefty mustard browns
to pleasant cream/tan warmth; one paper a very light gray.

Slavich has always come out clean. It has yet to be tested
with so little fixer so as to produce any color. Kentmere's
Bromide on the other hand takes on an ugly dark brown
-ish hue when tested with that same minimum amount.
Time, temperature, and agitation all being the same.

Counting square inches is not a method I'd use in
determining a fixer's exhaustion. And not just because
of the varying amounts needed by this paper or that.
Conditions of use and other factors vary. Dan

 

[Marco B]

Retained developing agent will gradually oxidize and cause a colored stain. The color depends on the developing agent(s) used.

Acid alone will not remove them. Actually a sulfite bath is best because sulfite reacts with oxidized developers and enables them to be washed out. Many people forget that this chemical is an aid to removal or prevention of retained developer stains.

PE

Thanks all for the comments, but I think Photo Engineer solved it. I'm pretty sure I have not had a "fixer" type issue. I test my fixer regularly, and it wasn't old. Nor did fresh fix remove the stains.

Actually, since I had been using a brush, I am now suspecting, as PE suggested, that the stains are caused by oxidized developer. During the printingsession, the brush had been lying around and of course the developer is bound to oxidize as hell in this situation. It is consistent with another observation: the stains are getting worse with the later on the day I printed them.

In addition, before I read PE's response, and since the prints were ruined anyway, I decided to throw them in a bath of regular house hold "soda", based on a hunch similar to PE respons. After some six hours soaking, most of the staining was gone. The hydroxide anions probably do something similar to the sulphite, suggested by PE, breaking down and reacting with the oxidized developer.

Next time I use a brush to develop prints, I will thoroughly rinse my brush after each print, preventing oxidized developer build up on the brush.

Actually, just one last question:

- How do I create a regular sulphite bath as PE suggested? :confused: What chemicals do I need and where can I get them?

 

[Marco B]

Those stains are silver. Dave's elbow grease method will work sometimes, but it depends on the tray and you'll never get it all. There is an easier way that will not cost a fortune. Pour some bleach (potassium ferricyanide) into the tray and let it sit for a while. That will return the silver to a silver salt which can then be dissolved and carried away with some fixer.

Although your suggestion may solve part of the issue, it's unlikely to remove all.

Bleach converts silver (Ag) to two substances:
- Silverbromide (Ag+Br-)
- Silverferrocyanide (Ag+Fe(CN)64-)

Silverbromide is of course easily dissolved in fixer, which is how fixer works. However, despite most metal-ferrocyanide compounds being vulnerable in alkaline conditions (just throw a cyanotype or blue toned print in fixer or a soda solution! , also see this excellent article by Wilco Oelen: http://woelen.scheikunde.net/science/photo/toners/toner.pdf), silverferrocyanide seems to be pretty stable. It won't be removed in fixer.

You can simply test this by totally bleaching a print, and throwing it in fixer. Although the light yellow image bleaches somewhat (removal of AgBr), it is not possible to completely remove it in fixer (most likely remaining Ag+Fe(CN)64-), nor does an alkaline soda solution remove it... would have been kind of nice if this would work and you would be left with bright white paper... could be used as a creative measure, partially obliterating photo's.

 

[Photo Engineer]

Just use 2% acetic acid stop with about 10 grams / liter of sodium sulfite (any kind) in it. This is not an exact requirement, just an extra sulfite bath of any sort to remove the developer.

If you are using alkaline fix, then just put some extra sulfite into the fix and use a good rinse instead of the stop.

I'm very happy my advice was useful. Thanks.

PE

 

[Vaughn]

But even with the scrubbing, don't the trays eventually get dis-colored with a stain that won't scrub off and doesn't get on the prints?

Probably...if you rub your finger on the tray and your finger isn't black, it probably won't get on the print.

But our trays are stainless steel (SS). We have been using the same trays since before I started to use the darkroom in 1977 (the trays are marked "Humboldt State College" and we became "Humboldt State University" in 1973.) Still not a stain on them. SS trays are expensive -- but no plastic tray would last 30+ years of continious student use (125 to 150 students per semester)!

Vaughn

 

[dslater]

Probably...if you rub your finger on the tray and your finger isn't black, it probably won't get on the print.

But our trays are stainless steel (SS). We have been using the same trays since before I started to use the darkroom in 1977 (the trays are marked "Humboldt State College" and we became "Humboldt State University" in 1973.) Still not a stain on them. SS trays are expensive -- but no plastic tray would last 30+ years of continious student use (125 to 150 students per semester)!

Vaughn

SS trays - that sounds great - to bad they cost an arm and a leg - I bet they look as good as when they were new. When I got my enlarger, the seller threw in a bunch of trays - most plastic and too dirty to revive. However 3 of them were those old ceramic covered trays - for all their age, there's not a spot of stain on them. I don't really use them for processing because the flat bottom makes them too difficult to use. I do use one of them for photo-flo so I don't have to worry about the photo-flo sticking to my plastic trays.

Dan

 

[dancqu]

However 3 of them were those old ceramic covered trays - Dan

Porcelain. I've some hard rubber and a glass tray. I think
the deposits in the developer tray may have nothing to
do with the processing of prints although that may
hasten the staining. I've not tested it but believe
it possible that those deposits derive from the
chemistry itself.

Just what are those deposits' chemical composition?
Likely no silver. If there were any silver in those deposits
I'd think silver salt solvency and solvent developer
chemistries and then worry about mushy grain,
loss of highlight detail, and ... .

By way of comparison, how well do plastic trays score
when used with sulfite free developers; Ascorbate
based developers? Stain free with vitamin C? Dan

 

[srs5694]

By way of comparison, how well do plastic trays score when used with sulfite free developers; Ascorbate based developers? Stain free with vitamin C? Dan

Agfa advertised that its Neutol Plus print developer, which is a phenidone/ascorbate developer, would not stain trays. I've never used it, though, so I can neither confirm nor deny this claim.

I mostly use phenidone/ascorbate print developers for B&W these days (E-72, DS-14, and Tektol). My print developer tray had already acquired some slight stains from using Dektol, though, and I also develop RA-4 color in the same tray, so I don't know how much of the continuing increase in stains is from my B&W developers and how much from the RA-4 developer. I suspect that the RA-4 is doing a lot more staining than the B&W developers, but I'm not 100% sure of that. Perhaps one day I'll get another tray to use only for my B&W developers....