Kallitype; new loss in dmax, coating or silver nitrate

Hello! First time poster, I am an mfa student at Yale school of art in the painting and Printmaking department but I have been working with Kallitype from digital negatives for going on a year now. After several times approaching the quality I was looking for I have had new problems arise. This time it is a drop in dmax and a sort of haloing with richer blacks at the edges of my coated areas but somewhat duller black in the middle. I mixed a new silver nitrate solution 2 days ago and I am not sure if I should suspect it is the culprit, or if it is a result of having to brush over the rod coated area to fill in some gaps? Some books recommend increasing the ratio of silver nitrate to ferric oxalate, but I am also considering trying a 12% solution vs the standard 10. I am using a few drops of 5% tween and sulfamic acid treated bfk. Up until recently I was getting rich blacks so I am not sure where the new problem is coming from

example

comparison to a previous coating
Any help greatly appreciated!
Opal

Hi, Welcome to Photrio.

I have a little confusion as to what is going on. Your first image black is darker than the second image which you say is supposed to be better. Perhaps full images might shed more light.

If the exact same chemistry is giving you two different Dmax'es, perhaps something changed in your procedure. Are you using the same amount of sensitizer on the paper (per sq. in.) as before? Is there more/thicker sensitizer left outside the print area than in earlier prints, depriving the center of adequate chemistry? Does this happen with the same negative as the earlier prints? There are a lot of variables that can come into play. Another example: how has the ambient humidity changed over the course of your early prints to the latest ones. Higher humidity will result in a more absorbing paper than lower humidity giving rise to better Dmax. On the other hand, if the humidity is too high, sensitizer can travel much deeper into the paper and end-result would be a weaker image.

I would recommend exhausting all of these other issues as potential sources of print variability your are seeing before trying to introduce a new chemical variable such as silver nitrate concentration or paper pre-acidification, etc.


:Niranjan.

Since you got good results before, I'd advise not to make large changes to your process. Barring contamination, your chemistry is probably OK but the problem might be in coating, humidity (as Niranjan said), exposure, or development. Are you replenishing your developer or using fresh each time? I add 130 ml of fresh developer per 9x12" print, discarding the developer at the bottom of the bottle, which turns dark or milky depending on its chemistry. Have you changed paper? It's frustrating, I know, because there are so many possible causes.

tnp651 said:

Since you got good results before, I'd advise not to make large changes to your process. Barring contamination, your chemistry is probably OK but the problem might be in coating, humidity (as Niranjan said), exposure, or development. Are you replenishing your developer or using fresh each time? I add 130 ml of fresh developer per 9x12" print, discarding the developer at the bottom of the bottle, which turns dark or milky depending on its chemistry. Have you changed paper? It's frustrating, I know, because there are so many possible causes.

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this time it looks like it was all user error! I mixed the developer with 2gm DRY dichromate not 2ml 5%!!! It must have been badly over restrained, proper dev is now back up and running

https://drive.google.com/file/d/1elST1CuAULJvXbxuVdqv9YeYJhZUDxN1/view?usp=drivesdk
image linked above more results soon!

Opal DeRuvo said:

this time it looks like it was all user error! I mixed the developer with 2gm DRY dichromate not 2ml 5%!!! It must have been badly over restrained, proper dev is now back up and running

https://drive.google.com/file/d/1elST1CuAULJvXbxuVdqv9YeYJhZUDxN1/view?usp=drivesdk
image linked above more results soon!

Click to expand...

The link above isn't accessible.

MattKing said:

The link above isn't accessible.

Click to expand...

How about now?

Opal DeRuvo said:

How about now?

View attachment 289693

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Full image link

We see one image, and a couple of not working links.
Convert your image to jpeg, and downsize to not more than 1000 pixels on the long dimension.