Rodolfo Namias' Sepiaprint

[Raghu Kuvempunagar]

Rodolfo Namias' Sepiaprint

I read Namias' 1901 article describing an iron-silver process. It is somewhat like a so-called “Van Dyke Brown” print, but uses citric acid instead of tartaric acid. It is not one of the historic processes that has remained popular today.

...

Namias recommended gold thiocyanate toner after fixing, so I mixed a weak toning solution of:

2.5 ml 0.2% gold chloride + 2.5ml 2% ammonium thiocyante in about 70ml distilled water.​

Toned in this for about 10 minutes, until it did not seem to be changing much.

Interestingly, Namias writes "it may be pointed out that it is impossible to tone it with gold before fixing. I have verified this, and find that no matter what may be the composition of the toning bath employed, it is impossible to modify to an appreciable extent the color of the image produced by plain water development. The image on Papier Sepia, so developed, does not contain those reduction products of silver salts which, as have shown elsewhere, is the principal cause for the easy deposition of gold upon the picture" and further "Papier Sepia, prepared without ferric oxalate, is not capable of being toned with platinum."

Any idea what is happening chemically here that resists toning before fixing?

 

[NedL]

Any idea what is happening chemically here that resists toning before fixing?

Hi Raghu,

No, and I can't understand why it seems different from VDB... the main difference is citric acid instead of tartaric. Despite what Namias wrote, I tried a few different toners, both before and after fixing. I'm not at home right now so I don't have my notes, but off the top of my head I remember trying Clerc's gold toner ( I think that's the one with some thiourea? -- anyway it was a thiourea gold toner ), gold and platinum toners made with weak citric acid, and gold toner made with ammonium thiocyanate. I was able to get shifts in image color but they were weak and tended to make the image lighter ( the platinum toners left a silvery image whether done before or after fixing... leaving a weak image without strong darks ). I also tried combinations too without much success. Nothing execpt gold thiocyanate looked very good.

I can confirm that for me, ammonium thiocyanate gold toner worked well both before and after fixing, which does not match what Namias wrote. I couldn't see much difference between the two, so it made the most sense cost-wise to wait until the image was fixed and dried and then decide if it was worth toning it. I came to think when Namias wrote "to an appreciable extent" he meant to darken or to change in a desireable way. I'll be home in a couple months and can post some examples if you are interested.

Actually, that's not the only mystery. I've used this process a lot to make "negatives" to then make cyanotype positives. I have a large number of these negatives that were "fixed" with just sodium sulfite, and none of them show signs of deteriorating. I also have a few that were "fixed" with sodium chloride, which leaves an interesting yellowish-gold image, and those haven't faded either. "Fixing" definitely does not mean the same thing as it does when silver nitrate is the light sensitive component! I have wondered if "fixing" in thiosulfate is also a kind of sulfur toning, since there appears to be intensification of the image.

 

[Raghu Kuvempunagar]

Hi Raghu,

No, and I can't understand why it seems different from VDB... the main difference is citric acid instead of tartaric. Despite what Namias wrote, I tried a few different toners, both before and after fixing. I'm not at home right now so I don't have my notes, but off the top of my head I remember trying Clerc's gold toner ( I think that's the one with some thiourea? -- anyway it was a thiourea gold toner ), gold and platinum toners made with weak citric acid, and gold toner made with ammonium thiocyanate. I was able to get shifts in image color but they were weak and tended to make the image lighter ( the platinum toners left a silvery image whether done before or after fixing... leaving a weak image without strong darks ). I also tried combinations too without much success. Nothing execpt gold thiocyanate looked very good.

I can confirm that for me, ammonium thiocyanate gold toner worked well both before and after fixing, which does not match what Namias wrote. I couldn't see much difference between the two, so it made the most sense cost-wise to wait until the image was fixed and dried and then decide if it was worth toning it. I came to think when Namias wrote "to an appreciable extent" he meant to darken or to change in a desireable way. I'll be home in a couple months and can post some examples if you are interested.

Actually, that's not the only mystery. I've used this process a lot to make "negatives" to then make cyanotype positives. I have a large number of these negatives that were "fixed" with just sodium sulfite, and none of them show signs of deteriorating. I also have a few that were "fixed" with sodium chloride, which leaves an interesting yellowish-gold image, and those haven't faded either. "Fixing" definitely does not mean the same thing as it does when silver nitrate is the light sensitive component! I have wondered if "fixing" in thiosulfate is also a kind of sulfur toning, since there appears to be intensification of the image.

I would be definitely interested in seeing your results. Please post them whenever convenient to you.

Are these in-camera negatives that you're talking about? So you coated translucent paper with Namias' sensitiser, exposed them in your camera and developed the paper in water? Wow! How long were the exposures?

Silver Sulphite as a fixer for Silver Nitrate is interesting. Is that why some recommend giving the developed VDB print a short treatment in dilute Sodium Sulphite solution before fixing?