Friends--
With Arches Platine lost in "reconfiguration" purgatory, I have been trying to learn how to work with other papers. In the process I have made a minor discovery on the use of glycerol (new to me at least, maybe you folks knew this all along).
Following lots of suggestions in threads on the Hybrid Site, I have come up with the following protocol.
1) Soak paper in 1.25% oxalic acid for five minutes, hang up to dry.
2) Coat with the following palladium solution:
LiPdCl 5 grams palladium chloride 1.00 milliliter
3.5 grams lithium chloride
50 ml water
ferric oxalate 13 grams FeOx in 1.00 milliliter
50 ml water
1.5% oxalic acid in 25% glycerol 0.25 milliliter
2% NA2 0.05 milliliter
3) Dry under a cool fan until emulsion does not stick to the negative and expose (for my "normal" exposure time when using platine).
4) Develop in saturated potassium oxalate. Then directly into 5% citric acid (no water rinse), followed by two EDTA/Na Sulfite baths and several water soaks.
I first tried acid pretreatment of the paper and putting acid in the emulsion -- but could never get a decent black. But some of the test prints looked like they were solarizing (getting lighter with added exposure) which in the past has been a symptom of not enough moisture in the emulsion. So, I added some glycerol to the mix and VOILA deep heavy blacks (Dmax between 1.3 and 1.4). So with this protocol I get good blacks and the prints clear nicely.
So far I have tried this approach with Fabriano Artistico, Rising Stonehenge, Strathmore 400, Somerset Velvet and Rives BFK. I have seen one problem. On some papers (Fabriano especially) the glycerol makes the paper slightly sticky to the negative. And if I dry to the point where it is not sticky, it is easy to overdry and end up with solarization. But on other papers this is not a problem.
Thanks for everyone's tips and advice. I still hope platine makes it back from the grave.
Cheers, Ron Reeder
The lithium palladium chloride is the metal salt used for Ziatypes; it is very hygroscopic. You might try eliminating the glycerin and just using a waterproof backing sheet (I use an old sheet of OHP) to help retain moisture during exposure. I regularly achieve log 1.45 with POP palladium on acidified Rives BFK and Fabriano Artistico without glycerin. You could also try adding a couple of drops of distilled water to the drop count.
Got word today in the U.K that they are indeed printing a batch of Platine as we speak, I was told around about 4 weeks to go before till delivery, when they will be sending samples out. Fingers crossed its a good batch. John Purcell are getting in 1000 sheets of Imperial size.
Like you Ron the problems with Platine have made me find new papers which I actually really like, they need oxalic acid but once you get used to the pre-wash its not to much of a hassle if you get a run going.
Philip-- It seems clear that my problem is a lack of sufficient humidity in the emulsion. Despite the fact that I am purposefully using hygroscopic lithium salts and adding extra water (with the oxalic acid I put into the emulsion). And I do not doubt for a minute that you and others are able to get good blacks without the glycerin (glycerol). But, results do vary, and I have not been able to do so.
I suppose I could go to extra effort to humidify my papers (build a humidity chamber, whatever) but I am beginning to think that the glycerin is a really easy and effective way to keep the humidity without going to all that trouble. So, if you already get good blacks, you do not need it. But if you are having trouble like me, you might find it an easy fix to the problem.
Cheers, Ron Reeder
1) Soak paper in 1.25% oxalic acid for five minutes, hang up to dry.
2) Coat with the following palladium solution:
LiPdCl 5 grams palladium chloride 1.00 milliliter
3.5 grams lithium chloride
50 ml water
ferric oxalate 13 grams FeOx in 1.00 milliliter
50 ml water
1.5% oxalic acid in 25% glycerol 0.25 milliliter
I first tried acid pretreatment of the paper and putting acid in the emulsion -- but could never get a decent black.
So, I added some glycerol to the mix and VOILA deep heavy blacks (Dmax between 1.3 and 1.4). So with this protocol I get good blacks and the prints clear nicely.
So far I have tried this approach with Fabriano Artistico, Rising Stonehenge, Strathmore 400, Somerset Velvet and Rives BFK. I have seen one problem.
Okay.
About a 15% solution of palladium salts. I assume the lithium is used to produce a more neutral tone.
Okay - 26% solution of FO.
Why is the oxalic acid used here?
Did you try brushing a 5% solution on the paper surface prior to coating?
1.4 DMAX is what I consider a good typical value though I've measured 1.5 when printing in very humid weather.
Have you tried Lana Aquarell <sp?> Pretty paper. Sandy King has finessed it for printing beautiful gold toned VDBs. About the same price as Platine.
Don
Don and Philip-- The lithium is there because you need some co-salt to get the palladium chloride to dissolve and I long ago started using lithium chloride as the co-salt since I had some Ziatype kit chemicals laying around. I never found a reason to change -- and as Philip points out, the hygroscopic nature of the lithium would seem to be an advantage.
I presoak the entire paper in oxalic acid and then hang it up to dry. Seems a better protocol than just brushing the acid on. But then, to have both belt and suspenders, I read that Sandy was adding some oxalic acid to some of his emulsions and I thought, a little more acid cannot hurt. Have not methodically tried leaving it out on various papers.
To tell the truth, though, even if I can now get several papers to work, I have not found a paper I like as much as the old platine.
Cheers, Ron Reeder
Dave when you get the paper and test would you let us know your thoughts.
Just spoke to my paper supplier, another 3 weeks until its supposed to arrive, apparently they are having problems making it! Thank goodness i have found alternatives.
...because you need some co-salt to get the palladium chloride to dissolve...
The paper is being reconfigured and is nothing to do with the company hand-over from my understanding. The recent paper batches have not been consistent and cannot be relied on.
Hi David,
Which Batch are you referring to? #5214/1 ??
Exactly one year ago was kindly asked by Bergger to test their new COT320 batch (almost for sure #5214/1) and the results were really bad with the coating rod.
It would be very useful to have those batches references.
Thanks
I have an unopened box of the big size, lot 5213 - anyone know if it's good or bad??
Thanks... Ben
Hi David,
You're lucky, the #5207 is a good batch. I've printed many sheets from that one.
Bergger sent me 16x20 sheets but I cut them down to smaller sizes and use 20x25 negatives for testing. Of course that the coating area was larger to have room for the Stouffer Tablet and PDN charts.
The emulsion had more Pd than Pd, as follows: 14-3-10-1(Na2_2.5%), PotOx Devel.
With this formula and using the COT batch you are using now I could easily reach a 1.50 DMax, using the rod.
Concerning the last COT320 batch produced by Bergger(??) I can update the info I wrote in the last post.
They are already selling the #5214/2 (I did't test it,yet) batch. So the new upcoming batch you were talking about must be the #5214/3 ?
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