Platinum Dmax

[Ian Leake]

Ian, I'm more interested in why you asked the question.

Hi Ian. I have to admit that I'm not really that interested from an aesthetic perspective, but it's an interesting technical challenge.

Personally I like using the soft muted tones, but sometimes I have a negative that needs to have plenty of darkness and shadows. My challenge is that although I can now print as black or blacker than all the reference prints I own, I feel that I should be able to go further. So that's why I'm interested in what other contemporary printers can acheive.

I suspect that I'm close to the limit of what can be achieved with Buxton. The deep blacks that I've seen on prints by Irving Penn, Studio 31 and Salto have been on heavier/whiter/smoother paper. That being said, I've also found some interesting ideas to explore by reading nineteenth century sources.

 

[doughowk]

I've primarily switched over to the Dichro method for contrast control; and am wondering if the expansion of contrast achieved thru higher quantity of Potassium Dichromate in developer would also increase the potential DMax? Also would temperature of developer affect DMax? It seems that when I use hot PO the DMax looks stronger, but I don't have means of testing this

Btw, Ian L., your book has been very helpful.

 

[Ian Leake]

I've primarily switched over to the Dichro method for contrast control; and am wondering if the expansion of contrast achieved thru higher quantity of Potassium Dichromate in developer would also increase the potential DMax? Also would temperature of developer affect DMax? It seems that when I use hot PO the DMax looks stronger, but I don't have means of testing this

Btw, Ian L., your book has been very helpful.

I don't think that the dichromate has an effect on Dmax (although I've not tested this). As I understand it, the dichromate does most of its work in the highlights.

I switched to room temperature developer some time ago on health grounds. After long printing sessions I was getting big headaches which I blamed on the amount of Potassium Oxalate which had evaporated into the air. I know of some other printers who got flu-like symptoms from this. I've not had any problems with room temperature PO.

That said, heating the developer definitely warms the tones and has other subtle effects too.

Both of these theories are simple to test. I'll do this when I'm printing next, and report back.

And thanks for your feedback on my book, Doug. My aim was to write a non-technical guide to Pt/Pd printing, and I'm glad people are finding it useful.

 

[Richard Boutwell]

I was testing the differences between Platine and Fabriano Extra white tonight, both single and double coating

Double coated Platine was 1.4 unwaxed, and 1.51 waxed. Single coated waxed was 1.4ish
Double coated Fabriano was topped out around 1.3 unwaxed, and 1.34 waxed. single coated was just rubbish. Think I am having issues with residual oxalic acid in the Fabriano after pretreating it. It smells like chemicals and the surface is very rough/dusty feeling.

I asked this in another thread, but does anyone know what the sizing on platine is, or how it can be replicated on something like Fabriano Extra White?

 

[Loris Medici]

...
Think I am having issues with residual oxalic acid in the Fabriano after pretreating it. It smells like chemicals and the surface is very rough/dusty feeling.
...

Could be (a.) not enough acidification or (b.) residual spiky calcium oxalate crystals affecting the surface qualities or (c.) both...

I left oxalic acid / Artistico combination because it was giving me a rough / gritty surface (coating with a puddle pusher / glass rod) and never turned back to it - for any paper! If not intimidated, just try dilute HCl (30ml 30-35% into 1000ml, or similar end dilution from weaker concentrations) and see if it works better for you...

Regards,
Loris.

 

[Ian Leake]

I can't advise on the Fabriano paper, other than to say stop using it if it doesn't give you good results. It's a false economy to save a few pennies by using a cheaper paper, but then go on to spend much, much more in wasted platinum and/or palladium.

 

[Ian Leake]

Also would temperature of developer affect DMax? It seems that when I use hot PO the DMax looks stronger, but I don't have means of testing this

I tested this today, Doug, and couldn't detect a meaningful and measurable difference in Dmax between two prints, one developed in room temperature developer the other in hot developer. They were otherwise identical double coated prints on Buxton. Of course it's always possible that a different paper will show something slightly different, but Buxton seems to be fairly consistent.

 

[doughowk]

Thanks, Ian, for testing. Maybe its the "browns" that appear darker to my eye. My work area is in the garage; and this time of year its easy to get warm/hot developer. I am using COT320 single coated.

 

[Ian Leake]

Thanks, Ian, for testing. Maybe its the "browns" that appear darker to my eye. My work area is in the garage; and this time of year its easy to get warm/hot developer. I am using COT320 single coated.

Yes, using hot developer will certainly boost the print warmth. It will also increase the speed at which the image appears - cold developer can take more time to work.

Out of interest, are you using any platinum with your COT320? If so, you may want to try making a pure platinum print - you may be surprised at how little platinum actually remains on the paper after processing - most of it gets washed down the drain...

 

[Loris Medici]

...
Out of interest, are you using any platinum with your COT320? If so, you may want to try making a pure platinum print - you may be surprised at how little platinum actually remains on the paper after processing - most of it gets washed down the drain
...

I find pt/pd printing very wasteful for that very reason... I much prefer to print vandyke and/or argyrotype and/or kallitype, and then pt or pd tone it. (At 99.9% of the times, I gold tone - because I like better the dmax and color it produces...) Tonality is still exquisite and expenditure is a magnitude lower! (I'm not a cheap Joe particularty; importing pt/pd stock solutions into Turkey can be very difficult. This way, I use up my stock in much much longer time...)

Regards,
Loris.

 

[Davec101]

Hi Ian. I have to admit that I'm not really that interested from an aesthetic perspective, but it's an interesting technical challenge.

Personally I like using the soft muted tones, but sometimes I have a negative that needs to have plenty of darkness and shadows. My challenge is that although I can now print as black or blacker than all the reference prints I own, I feel that I should be able to go further. So that's why I'm interested in what other contemporary printers can acheive.

I suspect that I'm close to the limit of what can be achieved with Buxton. The deep blacks that I've seen on prints by Irving Penn, Studio 31 and Salto have been on heavier/whiter/smoother paper. That being said, I've also found some interesting ideas to explore by reading nineteenth century sources.

Next time I'm in the V&A print room I might just ask them if they will let me take some densitometer readings from of the Penn prints. From what I recall they are mostly printed on Rives BFK, double coated on aluminium, don’t know many people who use this now. I suspect the dmax is around 1.6 - 1.7.
Studio 31 primarily use Arches Aquarelle and double coat. Last time I spoke to Georges at Salto they were using Taizan paper and were getting densities of over 2.0. I viewed some of the prints they had created at photo paris a while back but unfortunately they were behind glass, hope to visit later on in the year and see them for myself.

 

[Loris Medici]

...
Out of interest, are you using any platinum with your COT320? If so, you may want to try making a pure platinum print...
...

Just noticed the nuance. (Emphasis mine.) To my knowing, you can't make a pure pt print on COT 320 - because it has gelatin sizing. Pt doesn't like gelatin sizing, OR, it likes it a little too much - to the point of being reduced prematurely! (= Fog.)

 

[Ian Leake]

Just noticed the nuance. (Emphasis mine.) To my knowing, you can't make a pure pt print on COT 320 - because it has gelatin sizing. Pt doesn't like gelatin sizing, OR, it likes it a little too much - to the point of being reduced prematurely! (= Fog.)

The gelatin binds to the platinum and hinders it from forming an image. As a result, most of the platinum is washed down the drain along with the gelatin. Some people would consider this a waste of platinum

Gelatin does not bind to palladium in this way.

The conclusion is that if you want to print with platinum then you should not use COT320. But if you're happy with palladium only (e.g. by using the Na2 process) then COT320 is fine.

 

[Ian Leake]

Next time I'm in the V&A print room I might just ask them if they will let me take some densitometer readings from of the Penn prints. From what I recall they are mostly printed on Rives BFK, double coated on aluminium, don’t know many people who use this now. I suspect the dmax is around 1.6 - 1.7.

Didn't Penn bond his paper to aluminium so he could make multiple prints on the same sheet without registration issues?

 

[payral]

Last time I spoke to Georges at Salto they were using Taizan paper and were getting densities of over 2.0. .

Taizan paper I know, from Awagamy, is very thin - 36g/m2 - so it's very translucent may be they fix it on an another very dark paper and get better Dmax.

 

[Davec101]

Didn't Penn bond his paper to aluminium so he could make multiple prints on the same sheet without registration issues?

Yeah he did, some are referred to as multiple-printed platinum-palladium prints on aluminum. The bond that he used called Surlyn and was made by Dupont, unfortunately from what i hear, the bond is having lets say 'archival issues' and a few prints are having to be repaired as a result of using this technique.

 

[Davec101]

Taizan paper I know, from Awagamy, is very thin - 36g/m2 - so it's very translucent may be they fix it on an another very dark paper and get better Dmax.

Here is some more info from Michael Smith's site regarding the prints Georges made for him and Paula that i referred to :

We have had a series of sixteen large platinum prints made from a selection of our photographs from Iceland. They are made at the Salto Platinum Atelier in Belgium. We have never before seen platinum prints as rich as these.

Paula’s prints are printed on translucent handmade Japanese Taizan paper 23" x 29". Michael’s prints are printed on Arches Platine paper and are one meter wide—15" x 39".

The prints are stunning. Many contemporary platinum prints are “soft” and lack rich blacks and a full tonal range, and many people mistakenly believe that this is the way platinum prints should look, but platinum prints can be as rich as silver prints (those by Irving Penn are a good example).

To make these prints our original negatives are scanned; then five enlarged digital negatives made from each one are printed in register with multiple exposures—a lengthy and arduous process.

http://www.michaelandpaula.com/mp/html/platinumprints.html

 

[doughowk]

Attended a Michael & Paula workshop last year during which they showed us their Platinum prints. The prints were very impressive, especially Michael's on Arches Platine. I was not doing pt/pd at the time so didn't think of asking about the process other than the multiple negatives. Single coated? I presume that to avoid shrinking, these are single processed with the contrast being controlled thru exposure with each registered negative. Then processed as for normal contrast.

 

[payral]

I found a piece of Taizan paper. A sample one but big enough to print a steptablet. I print 100% palladium, one coat, use potassium oxalate for development at room temperature (23° C) and got a Dmax of 1.42
I also checked my prints on Arches Platine and my average Dmax for exhibition prints is between 1.32 and 1.36. Most are pure palladium prints.

 

[Davec101]

I found a piece of Taizan paper. A sample one but big enough to print a steptablet. I print 100% palladium, one coat, use potassium oxalate for development at room temperature (23° C) and got a Dmax of 1.42
I also checked my prints on Arches Platine and my average Dmax for exhibition prints is between 1.32 and 1.36. Most are pure palladium prints.

With all this talk about dmax I did a few tests yesturday and the highest reading I got was 1.78, Platinum/Palladium on Arches Platine non waxed (see attached). I put down a heavy single coat, humidity was 49%. Potassium Oxalate Developer (Dichromate as contrast contol)

 

[John Jarosz]

Back in the day when I tried Palladio platinum paper my max density was about 1.4. Their paper was matte and the appearance was much better after the prints were dry mounted. My carbon prints max out at 2.05 Dmax. This thread has been going on for quite a while and I always meant to measure some of my prints. So i finally did it.

 

[Davec101]

With all this talk about dmax I did a few tests yesturday and the highest reading I got was 1.78, Platinum/Palladium on Arches Platine non waxed (see attached). I put down a heavy single coat, humidity was 49%. Potassium Oxalate Developer (Dichromate as contrast contol)

Having checked my densitometer with a friends analogue one, my readings seem to be out for some reason and will have to send it off for recalibration. The more accurate readings from his meter were averaging 1.4 to 1.5 on Arches Platine non waxed.

 

[Davec101]

Initial Results from multilayered platinum print.

I had some time today to finally investigate whether Penn’s method of multilayered platinum prints makes a significant difference to the dmax and also the overall appearance compared to a single coated platinum print.

The initial printing paper was bonded to aluminium (this maintains dimensional stability of the paper and does not require sizing) and then coated/exposed and developed for the first layer, once this had finally dried I then recoated with the same drop count and then re-registered the print and then exposed and developed for a second time.To my eye the final dried down multilayered platinum print has an overall richer look to it, the numbers show a difference of is around 0.17 log.

Is this significant, well I was expecting slightly more and will require further testing. I will apply another layer tomorrow to see what difference that makes. I believe with some prints Penn may have layered three times. I would expect a gum layer to make more of a difference at this stage and will test this over the next couple of weeks.


First layer dried down readings

Recoating for a second time

Second layer dried down readings

 

[Marco B]

Emulsions and paper

It is partly off-topic maybe, but since paper structure in relation to emulsions is discussed as well, I thought I would post these page from James M. Reilly's "Care and identification of 19th century prints".

It shows high magnification (up to some 40.000x) electron micrograph images of cross sections through paper and light sensitive emulsions / coatings, including Pt, giving a better idea of how these emulsions integrate or combine with the paper layer.

I found it quite intriguing to see... :confused:

Marco