Toning scum

[David Lingham]

I've a problem when partially selenium and then weak sepia toning Kentmere fineprint WT. At the end of the final wash there is a brown scum on the prints. This can be removed by rubbing the wet print on a flat surface with some paper towel, but what is causing it? Is it a natural result of using dilute toner? The prints look fine when dry, and appear as I intended them to. I'm using Fotospeed selenium and ST20 sepia toner and an archival washer.

Procedure:
presoak 30mins
selenium 1+15 2mins
wash 60mins
bleach @ half strength 60-90 secs
wash 60mins
tone @ half strength 2-3mins
final was 60mins

 

[fschifano]

Only when toning? Could be that your tap water isn't as clean as you thought. Same thing happens (toned or not) to me if I use straight tap water. After attaching an inline water filter, the problem went away.

 

[Ian Grant]

It's quite common with some toners, as I always dry the front & back of my prints with some kind of towel it's easy to remove. I get it happen with selenium toner. It's far better to remove it before the prints dry, filtering the water makes no difference..

Ian

 

[PVia]

Tim Rudman talks about it in his Master Printing book...I believe a 3% acetic acid dip is used to remove it, which is seen more on RC papers than FB. I don't have the book handy right now, so not sure of the exact dilution and time.

 

[Stoo Batchelor]

I've a problem when partially selenium and then weak sepia toning Kentmere fineprint WT. At the end of the final wash there is a brown scum on the prints. This can be removed by rubbing the wet print on a flat surface with some paper towel, but what is causing it? Is it a natural result of using dilute toner? The prints look fine when dry, and appear as I intended them to. I'm using Fotospeed selenium and ST20 sepia toner and an archival washer.

Procedure:
presoak 30mins
selenium 1+15 2mins
wash 60mins
bleach @ half strength 60-90 secs
wash 60mins
tone @ half strength 2-3mins
final was 60mins

David

I don't wish to appear to come over as 'Mr know it All' but I would say that your washes in between toners is way, way too much. Some would argue that my 5 minute wash after selenium toning is not enough, but 10 minutes would be more than enough before bleaching. A few minutes in the wash after bleaching would be ample, though 5 would be safer, before the print enters the sepia.

Best

Stoo

 

[dancqu]

At the end of the final wash there is
a brown scum on the prints.

Procedure:
presoak 30mins
selenium 1+15 2mins
wash 60mins
bleach @ half strength 60-90 secs
wash 60mins
tone @ half strength 2-3mins
final was 60mins

Just currious. What is in that last toning bath
that leaves a brown scum? Dan

 

[Tom Stanworth]

I think toning scum is a fabulous idea. It will make it much easier to identify miscreants.

 

[Vaughn]

"I have always been told" that one should not bleach prints that have been selenium toned...but instead sepia tone first, then selenium tone.

But this is just what I have always been told...but what the heck, if it works (or does it?) go for it.

Vaughn

 

[David Lingham]

Thanks for all your answers.

Vaughn, I partial selenium first to tone the shadows and then briefly bleach the hilights to add tone there.

Stoo, in the past when I've used a shorter wash cycle I've experienced staining when doing multiple toning, especially with MGWT. Thats why I've arrived at these times, to remove all traces of selenium before going the next step, more so if I'm going to gold tone after selenium. Also I only use FB paper.

Dancqu, the last toning bath is half strength Fotospeed ST20 ie 50mls pt2 + 10mls pt3 +1.5 litre water.

Ian, Thanks for putting my mind at rest, just scum thats all.

Thanks guys

 

[Stoo Batchelor]

Stoo, in the past when I've used a shorter wash cycle I've experienced staining when doing multiple toning, especially with MGWT. Thats why I've arrived at these times, to remove all traces of selenium before going the next step, more so if I'm going to gold tone after selenium. Also I only use FB paper.

Of course whatever works for each and every one of us David, though overwashing does come with its own problems.

I enjoyed my visit to your site. I liked number 18 in gallery 2. Always good to see work from a fresh 'eye' Very nice indeed.

Best

Stoo

 

[David Lingham]

Thanks for the comments Stoo.

 

[dancqu]

The Brown Scum's Composition?

Just currious. What is in that last toning bath
that leaves a brown scum? Dan

So nobody knows or will volunter a response. So I'll put
the question a little differently. Of what is that brown
scum composed? Shouldn't we know? Dan

 

[Maris]

My guess would be that the brown scum is elemental sulphur.