Kallitype variability and how to control it

[philldresser]

I would like to better understand the variables that affect granularity of image when printing with the kallitype process.

Last night I printed a batch of an image (x9) using the following variables & procedure and received significant varyiation in results in relation to granularity (and less so, colour of image)
and I am at a loss to understand why?

Paper : Arches Platine
Sensitizer : Silver Nitrate/ Ferric Oxalate

Paper was double coated with sensitizer with 5 mins drying between coatings. All then air dried for 30 mins and then cold blown for 5 mins with hairdryer.

All images were then exposed for the predetermined time (12 mins in this case)

Each print was subsequently processed using

Developer : Sodium Citrate (@ 19 C room temp) for 3 mins
Clearing Bath : Citric acid
Fixer : Hypo (sodium thiosulfate)

The first 4 images were fine but showed a moderate amount of grain similar to the image I posted last week which I was reasonably pleased with.

Original Image​

The 5th image however was extremely smooth showing no grain at all. From 6 onwards the grain returned.
I will scan the variations tonight and post as attachments in this thread.

Does anybody have any insight on how I can control this? The smooth print is sublime in tonality and I wish understand what happened so that I can replicate it in future.

Thanks

Phill

 

[sanking]

Did you renew or replenish the chemicals during the working session? If not, that by itself would explain the variations and is the most likely culprit IMO.

Also, the humidity of the work room will typically increase significantly from the beginning to the end of a work session, and that may also have impacted your results. Most people find an RH meter very useful in printing with the iron processes.

Sandy

I would like to better understand the variables that affect granularity of image when printing with the kallitype process.

Last night I printed a batch of an image (x9) using the following variables & procedure and received significant varyiation in results in relation to granularity (and less so, colour of image)
and I am at a loss to understand why?

Paper : Arches Platine
Sensitizer : Silver Nitrate/ Ferric Oxalate

Paper was double coated with sensitizer with 5 mins drying between coatings. All then air dried for 30 mins and then cold blown for 5 mins with hairdryer.

All images were then exposed for the predetermined time (12 mins in this case)

Each print was subsequently processed using

Developer : Sodium Citrate (@ 19 C room temp) for 3 mins
Clearing Bath : Citric acid
Fixer : Hypo (sodium thiosulfate)

The first 4 images were fine but showed a moderate amount of grain similar to the image I posted last week which I was reasonably pleased with.

Original Image​

The 5th image however was extremely smooth showing no grain at all. From 6 onwards the grain returned.
I will scan the variations tonight and post as attachments in this thread.

Does anybody have any insight on how I can control this? The smooth print is sublime in tonality and I wish understand what happened so that I can replicate it in future.

Thanks

Phill

 

[philldresser]

Sandy

The session was only 9 5x4 contacts. Would I need to replenish for such a small batch which is equivalent to 2 8x10's?
What I found frustrating was that the best image was in the middle of the session and not with the 'fresh' chemicals.

I will look into the RH monitoring. Currently using the kitchen so addin RH would be easy.

Phill

 

[doughowk]

It does seem quite difficult with Kallitypes to repeat a successful image. With fresh chemicals for each process, you lose possible benefits of aged developer. And how do you control those benefits? I'm trying to settle on a single developer mix since I find great variations between sodium acetate & sodium citrate (besides color, acetate seems faster). Tartaric acid is suppose to be helpful (acts as restrainer & clears highlights); but how does one judge when it needs replenishment. Potassium dichromate can be used to increase contrast, but it appears to lose effect with use, and also needs replenishment. And now I see that I need to control RH. All very confusing ;-(

 

[philldresser]

Doug, I feel your pain! I would love to get the process more consistent as it is a great process to work with.

Having looked through all my literature over the weekend regarding kallitypes I find no mention of humidity control and it's effects. Perhaps it is mentioned in Dick Stevens book, but I have yet to find a copy in my reach. The only reference point I could find was that the paper has to be bone dry when exposed (Barnier). I have read about other processes where RH is critical and should have probably put all the clues together for kallitypes as well, but I have never considered it.

One thing I will do now is conduct a test with my normal procedure and one where I know the paper is thouroghly dried to see if this is the 'grain' variable.

I relation to the above topic, what RH should I be looking for for Iron process work and does anyone have any tried and tested methods for keeping it stable in a non darkroom environment (Kitchen)

Cheers

Phill

 

[Colin Graham]

As to the sodium acetate, I've had no luck with replenishment. After a week or so I get a pretty serious mottling artifact that decanting and filtering wont fix. But the contrast seems better than citrate with the same amount of dichromate and I really like the color a lot, so I'm going to continue using it anyway. I use it with 3 g tartaric acid per liter. Anyway, I find that as along as I'm using fresh solutions I'm getting very repeatable results on Arches Aquarelle soaked in a 5% citric acid bath. Probably beginner's luck, but I hope it lasts!

 

[sanking]

Having looked through all my literature over the weekend regarding kallitypes I find no mention of humidity control and it's effects. Perhaps it is mentioned in Dick Stevens book, but I have yet to find a copy in my reach. The only reference point I could find was that the paper has to be bone dry when exposed (Barnier). I have read about other processes where RH is critical and should have probably put all the clues together for kallitypes as well, but I have never considered it.
Phill

Humidity plays almost exactly the same role in kallitype that it does in DOP pallaidum using ferric oxalate. For best results it needs to be on the high side, say 55% - 65%, and you should be consistent in exposing the paper at some pre-determined time from the time you finish coating. If this information is not in my articles on kallitype I probably need to add it. If the humidity is too low, or if the paper is allowed to dry out too long, the result will be a reduction in Dmax. RH also affects the scale of the process, with low humidity giving short scale (log 1.7 or less) and high humidity giving long scale (2.2 or more). As a general rule I think it best to match the DR of your negative to conditions of humidity in your workroom. For example, if the humidity is consistently very high, say 65% or more, develop your negatives to a DR of about 2.4, and vice-versa with low humidity.

It is very imporant that the chemicals at the front end (before toning) be fresh. This includes not only the developer but also the clearing baths. If the clearing baths are too strong, or if you clear too long, some of the silver image will be bleached and you will lose Dmax. I use a 3% solutin of citric acid and renew the solutions frequently. And time carefully clearing time.

Dichromate, used as a restrainer, does deplete with use, but if you replensih the developer in a systematic way, say 100ml of fresh solution for every 8X10 print (or equivalent) you can just add dichromate back at the same time. Of couse, if you negatives have a very high density range you may not need to use dichromate at all. My negatives for kallitype have DR of about log 2.0 and I need only about 1ml of a 5% solution of dichromate per liter of developer to completley clear the whites.



Sandy King

 

[doughowk]

Humidity - I couldn't find any mention in Dick Stevens book except for drying the sensitized paper. He states:

Coated kallitype paper should be thoroughly dried immediately after coating. Quick-drying prevents the sensitizer from running and keeps it on the surface of the paper. Sensitizer that sinks into the fibers does not produce as sharp an image as sensitizer that is quick-dried on the surface

For processing, Sandy's info appears the most explicit.

 

[sanking]

Humidity - I couldn't find any mention in Dick Stevens book except for drying the sensitized paper. He states:
For processing, Sandy's info appears the most explicit.

I agree with what Dick Steven's writes about quick drying. It helps a bit if you direct the air from a fan directly on the print right after coating. A hair dryer on warm for a few seconds will also do the trick.

Regarding Dick Stevens and his book, it is important to note the fact that he did most of the reserach for this book some two decades ago when many of the best practices we now know about palladium and platinum printing were not widely undrestood. The importance of humidity is in that category.

I generally work at 55% RH. In practice I coat the paper, direct air on it while horizontal for a couple of minutes, then hang to dry. I always expose at about 15 minutes from the end of coating, at which time the paper will be very dry to the touch, and will have started to curl slightly.

Sandy

 

[Russ Young]

I have a few suggestions on dimensions not yet raised.

1. The paper should be brought to the required humidity level and allowed to 'rest' there for a day or two; this is standard printmaker's technique.
2. Are you absolutely consistent with the amount of sensitizer applied?
3. Are you consistent with the time you spend spreading the sensitizer and the amount of pressure used?

If the paper was appropriate, the only graining problems I had with Kallitypes were when using too much sensitizer or abrading the paper surface as I coated. Your mileage may vary however.

You might also check my chapter in Coming Into Focus on Kallitypes.

Good luck,
Russ

 

[philldresser]

Russ
2 - I can answer Yes. Syringed amount on same marked out area.
3 - I think so although this is subjective
1 - is a definite No at this point in time. I batch coat around 12 5x4 at the same time. By the time I have covered the 12 I start to force dry the first. Once dry i start printing, one at a time, so the duration between drying and printing gets progressively longer.
Phill