post alternative techniques

[Vincepad]

Question: I've been playing with gum dichromate printing for a few weeks and have been having some decent success printing on Canson Aquarelle 140lb/300gsm, Strathmore 400 series 140lb/300gsm, and to a lesser extent Arches Aquarelle 140/300. I've been printing on all three without adding any extra sizing.

Today I decided to size my paper with Knox Gelatine (7g/200mL water, hardened with 3mL of glyoxal in the sizing solution - i.e., following Katharine Thayer's method). Well, suddenly my exposure times (using a UV exposure unit that I've been using all along) went from 3-8 minutes to less than 30 seconds in order to get a print that clears the highlights. And yes, somehow, I'm getting the gum in the shadows to harden such that it doesn't come off during development.

My question: is it possible for sizing, of all things, to have such a dramatic effect on exposure time? I mean this is just silly.

[sanking]

I sure hope so! Like I said, my digital negatives are likely to pose some challenges to me in terms of contrast control, so I would be very happy if you could share your views on that issue with me. I get some mixed results when reading about controlling contrast by varying the silver nitrate/oxalic acid ratio in the sensitizer (no specific information to be found, but a suggestion by a printer who indicates he plays with this paramter) and adding dichromate to the developer (should increase contrast, but apparently by simply truncating the upper part of the curve?).

I have not printed with kallitype in several years, but at one time it was one of my favorite alternative processes. I have article on my web site of the working procedures that I used. http://www.sandykingphotography.com/...litype-process

When I wrote the article, a decade or more ago, I was still printing primarily with ULF camera negatives and had to find some way to control contrast since it is very hard to nail that completely in exposure and develoment. There are two ways to control contrast with the process, 1) you can add a bit of dichromate to the emulsion, or 2) you can add dichromate to the developer. Small amounts can have a huge impact so I added it to the developer. From the article,

"Contrast can be controlled by the addition to the developer of a few ml of a 5% solution of potassium dichromate solution. The practical limit ranges from as little as 1 ml per liter of developer up to about 16 ml per liter. This allows the use of negatives from a DR as low as about 1.2 to a maximum of about 2.2. If too much dichromate is added, printing times will increase considerably and the image will take on a granular look. For negatives that have been developed to a DR of about 1.8 add about 2ml of the 5% potassium dichromate per liter of developer."

Kallitype is a beautiful process and when toned with gold, palladium or platinum, quite permanent. With noble metal toning a very high percentage of the silver is replaced by the more noble metal. The look can be almost identical to pt/pd, when toning with platinum or palladium, or a very beautiful cool blue black, with gold toning.

Sandy

[andreios]

... or a very beautiful cool blue black, with gold toning.

Sandy

Yes, that is quite right - and quite beautiful.


Wreath by andreios, on Flickr

(but at least for me it's difficult to match when scanning the print)

[UlbabraB]

Piazza San Marco by Filippo Natali, on Flickr

Piazza San Marco (Venice), 5x7" Van Dyke brown print on Fabriano Artistico, 15 minutes pinhole exposure.

[Ramiro Elena]

Fantastic Filippo.

[koraks]

I have not printed with kallitype in several years, but at one time it was one of my favorite alternative processes. I have article on my web site of the working procedures that I used. http://www.sandykingphotography.com/...litype-process

Thanks for posting the link; I hope it'll serve others - I had already found it and I think I must have read it at least three times now. I will revisit it many more times, I'm sure! Your article was the primary reason for me to order the chemicals and I can't wait to get my hands dirty on this process! (Hopefully not as dirty as on carbon prints though - and yes, I do wear gloves whenever toxic chemicals are involved.)

When I wrote the article, a decade or more ago, I was still printing primarily with ULF camera negatives and had to find some way to control contrast since it is very hard to nail that completely in exposure and develoment. There are two ways to control contrast with the process, 1) you can add a bit of dichromate to the emulsion, or 2) you can add dichromate to the developer. Small amounts can have a huge impact so I added it to the developer.

I was only vaguely aware of the possibility of adding dichromate to the sensitizer. It seems like a more flexible approach than adding it to the developer, as it will eradicate the need to store different batches of developer with different concentrations of dichromate. I'll try to do without dichromate at first, but given the nature of the negatives I use, I'm afraid I'll have to resort to it anyway. Do you have experience with varying the ratio of oxalic acid to silver nitrate to boost the density? I imagine it could help in accommodating for thin (digital) negatives like in cyanotype and analogous to increasing the pigment in carbon tissue.

Kallitype is a beautiful process and when toned with gold, palladium or platinum, quite permanent. With noble metal toning a very high percentage of the silver is replaced by the more noble metal. The look can be almost identical to pt/pd, when toning with platinum or palladium, or a very beautiful cool blue black, with gold toning.

Perhaps one day I'll try my hand at gold toning, but I want to learn the basic process first because I start spending a lot of money on gold chloride. That stuff is seriously expensive, especially from the source where I get my chemicals from...I am considering trying selenium first when I get to the stage where it makes sense to tone my prints. I'm aware that it doesn't even come close to gold or pt/pd in terms of longevity, and I notice that many don't care for the tones it creates, but I'll have to find out for myself. It's certainly less cost prohibitive.

I also saw a couple of kallitype prints by Wolfgang Moersch which he mentioned having toned with carbon toner. I can't find much info on that, apart from his own MT2 carbon toner, but I can't find anything about what it does in terms of chemistry. There is a page on his site with examples (German only), but still no clue as to the chemistry. I tried contacting dr. Moersch once last year, but he didn't respond. Perhaps he was busy making gorgeous images...

[sanking]

Koraks,

Glad that you found the article useful. And good luck with your work.

BTW, it is probably better to keep your hands clean with kallitype than with carbon. With carbon you can just wash off the pigment, but silver nitrate on your hands will cause a very dark stain that lasts several days!!

Adding dichromate to the sensitizer should work, but only a small amount will be needed. Even 5 ml of a 5% solution in a liter of sodium citrate develope will have a significant impact on print contrast.


[QUOTE=koraks;1206377]Thanks for posting the link; I hope it'll serve others - I had already found it and I think I must have read it at least three times now. I will revisit it many more times, I'm sure! Your article was the primary reason for me to order the chemicals and I can't wait to get my hands dirty on this process! (Hopefully not as dirty as on carbon prints though - and yes, I do wear gloves whenever toxic chemicals are involved.)

Sandy

[cbk]

van dyke,

[captainscot]

8X10 Gold toned Kallitype on Arches Platine

[koraks]

Beautiful image, captainscot! I suspect the color is a bit cooler in the actual print than it appears on my monitor, but I like it how I see it now as well!

Btw, I have some questions concerning kallitypes and Van Dyke. Because I didn't want to further disturb this thread by lengthy Q&A's, I created a new thread in the Darkroom forum. Perhaps the people who read this thread and have experience with the chemistry in these processes could help me out, if you will.