using Na2 for contrast on palladium?

[TheFlyingCamera]

That's a fairly long time for a base exposure... especially if you have to add a stop or two... you could actually start running into reciprocity with those times... and if the prints are getting hot, they're drying out, which is also extending the exposure time...
Hopefully your new fluorescent unit from B&S will run a lot cooler and take care of that problem. I've got a set of cheapo blacklight fixtures from Home Despot that I screwed onto the bottom of a shelf, and they work quite nicely for this purpose, and they have enough ventilation that they don't heat up very much at all, even with a 20 minute exposure - the glass of my frame is cool to the touch.

 

[RobertP]

If you are going to be doing a lot of ULF pt/pd printing. Buy yourself 2-2ml pipettes and 1-1ml pipette and use Arentz's table in his book to the amount of na2 in relation to the amount of FeOx and Pd based on the density range of the negative. This will totally eliminate the need to count hundreds of drops and its much more accurate. If you have Arentz's book go to page 58-59 ( second edition) Robert

 

[RobertP]

Also by using pipettes you eliminate the need for reducing your solution to 10% and 5% solutions. Drop sizes can vary from dropper to dropper and also change by the way you hold the dropper. Pipettes are way more accurate. Anything that requires 1ml of total solution or more I'd use pipettes.

 

[RobertP]

As far as a light source goes. I've owned the 18x20 Edwards Eng. box that B&S sells. But for half of the price of that you can find a NuArc 26 1K plate burner, used. The UV box makes it practically impossible to dodge and burn where as the point light source of the Nuarc makes it much easier since it is a foot or so above the vacuum table. Plus with the Nuarc you have the use of a vacuum table which is much better than a print frame IMHO. The NuArc also has a light integrator which allows you to really dial in the exposure times. I found mine on the auction site a few years ago for 50.00 but they normally go in the 400.00 or so range. If money is no object opt for the AmerGraph ULF-28 advertised in this forum. I want one of those. But either light source will work, UV box or plate burner. I just got better results and more control with the NuArc.

 

[michael9793]

I have checked his book but I have a original copy printed in 2000. so i will have ot find it in the book. I'm sure it will be in there.
thanks for all the info

mike a

 

[RobertP]

I'm not sure Dick covered the Na2 process in the first edition with any depth. I have it here somewhere. I'll try to find it. I know he covers it indepth in the second edition though.

 

[Vaughn]

I find it interesting that I have heard the full gambit of opinions on how best to use Na2.

1) use an extra drop of FO per drop of Na2
2) just substitute Na2 drop for drop with metal
3) add the Na2 on top of the one's normal number of drops of FO and metal

And then there is the:

A) never use any of the regular Platinum salt when using Na2
B) no problem using drops of the regular Pt salts with Na2

I have a feeling all variations work just fine. If I had the time and inclination for testing, I would probably try all combinations of the methods with the same negative. But I don't, so I won't. I think I'll stick with what I have always done (#2B) and occasionally #2A.

Any defivinitive testing done with these variables out there?

Vaughn

 

[Paul]

I am still a bit confused about terminology here. (I am thinking of trying platinum printing after dabbling in kallitypes, more out of curiosity than dissatisfaction with the kallitype process.) Based on what I have read here, people seem not to like the A+B method of contrast control and prefer the Na2 method. Looking at the Bostick and Sullivan site, the Na2 kit comes with ferric oxalate, palladium and 20% Na2 as sensitizers. On Dick Arentz's web site he lists the drop count for a medium contrast negative (1.4) as 6 drops ferric oxalate, 6 drops palladium and one drop 20% Na2 . It seems to me that this is more a palladium print with a smidge of platinum (one drop) to control contrast, and not a "platinum" print. I hate to appear dense, but am I missing something?

 

[TheFlyingCamera]

I am still a bit confused about terminology here. (I am thinking of trying platinum printing after dabbling in kallitypes, more out of curiosity than dissatisfaction with the kallitype process.) Based on what I have read here, people seem not to like the A+B method of contrast control and prefer the Na2 method. Looking at the Bostick and Sullivan site, the Na2 kit comes with ferric oxalate, palladium and 20% Na2 as sensitizers. On Dick Arentz's web site he lists the drop count for a medium contrast negative (1.4) as 6 drops ferric oxalate, 6 drops palladium and one drop 20% Na2 . It seems to me that this is more a palladium print with a smidge of platinum (one drop) to control contrast, and not a "platinum" print. I hate to appear dense, but am I missing something?

Your description of it is how I'd call it too. That NA2 mix sounds awfully strong to me though, for a "medium contrast" negative. I suppose it is correct for a negative that is "medium contrast" for silver-gelatin printing.

 

[Paul]

So a person who calls himself a platinum printer and uses the Na2 method is really a palladium printer who uses a dash of platinum to boost contrast.

Dick Aretnz calls for one drop of 20% Na2 as an addition to 6 drops palladium and 6 drops ferric oxalate when printing a negative with a density range of 1.4 here on his web site. What would you use for such a negative?

 

[Paul]

I think what confused me is that I was thinking in terms of the A+B method when I looked at Arentz's web site. Under that sytem, a negative with a range of 1.4 would be a normal mid-range negative. That is, however, not really contrasty at all by palladium standards. I notice also that he calls his chart "Standard Negative Contrast Ranges for Palladium Prints Na2 (Sodium Chloroplatinate) Method". I guess that answers my other question too.

 

[TheFlyingCamera]

To me ( I've never done a densitometer test of my film, but I've adjusted my processing methods to yield negatives that print well in pt/pd with minimal contrast agent), a 5x7 negative printed on COT320 and properly developed will require the following mixture: 7pt/pd (whatever blend you want to use... I typically go 4pt:3pd), 7FeOx, 1 drop 7.5% NA2. A CONTRASTY negative would require no agent at all on a pure palladium print, as palladium is inherently less contrasty than platinum.

Bear in mind that the Dick Arentz book, while an exhaustively researched and superbly compiled reference volume is still prone to his own personal biases and tastes. Dick likes 'em punchy, kinda the way Ansel started printing everything at grade 4 in his later years. Contrast is a matter of interpretation. Feel free to see what actually looks good with your own negatives and what appeals to your own eye, rather than following some pre-determined mathematical formula.

 

[Paul]

You just cleared up my other source of confusion. The Bostock and Sullivan website lists the Na2 kit as a platinum/palladium kit when it is, to my mind, more accurately described as a palladium kit with a platinum contrast agent. I did not realize that you were adding platinum to the mix as well as using the Na2 contrast agent. That clarifies things. If the sensitizer is a mix of platinum and palladium with the addition of Na2 for contrast control, that would in fact be a platinum print. I assume that the platinum solution you are using (in addition to the Na2) is pottasium chloroplatinate or solution #3 as sold by Bostick and Sullivan?
Thanks.

 

[TheFlyingCamera]

Yes that is correct.

 

[scootermm]

wow. this again.

phew.

Biggest suggestion is whoever is interested in learning about Na2. PLEASE read the Arentz book (2nd addition) for really good, clear and chemically sound information.

 

[RobertP]

Regardless of which platinum salt you use whether it is potassium chloroplatinite or sodium chloroplatinate you are still adding platinum to the palladium so with either method it is a platinum/palladium print. Sodium chloroplatinate just reduces the iron at twice the rate compared to potassium chloroplatinite. But platinum is platinum gentlemen. If you drop one drop of Na2 in then it is no longer just a palladium print. But you can call it anything you want. Robert

 

[nick mulder]

To anyone thinking about getting into NA2 over chlorate (much better tonality) here is what has worked for me:

I simply add one drop %20 to a 1:1 mixture of FeOxd salt of around 30:30 drops (60 total) - which is the same as one drop %10 for 15:15 and %5 for ~7:7 and so on (the little extra amount of water has no effect) - the contrast ratio working this way comes from the total amount of FeOxd rather than thinking about how much NA2 to add (same thing, just the other way round)

I work solely in %20 and do many coatings at once ...

My portraiture negs are pretty much always the same contrast - you will no doubt need different ratios for the look you are after, test and see - Best way is just to jump in a try it, you'll work something out.

I dont care if I call them palladium prints over platinum >> NA2-o-type ? heh

 

[bill schwab]

... a 5x7 negative printed on COT320 and properly developed will require the following mixture: 7pt/pd (whatever blend you want to use... I typically go 4pt:3pd), 7FeOx, 1 drop 7.5% NA2.

Maybe I am missing something in this thread, but the way I've learned this is that it useless to use any Na2 in a mixture that contains a blend of PD and PT. Can someone clarify this? It would be a shame to have people wasting time and expensive Na2.

 

[photomc]

Maybe I am missing something in this thread, but the way I've learned this is that it useless to use any Na2 in a mixture that contains a blend of PD and PT. Can someone clarify this? It would be a shame to have people wasting time and expensive Na2.

Bill, check out (there was a url link here which no longer exists)...and check what Clay and others have to say on the subject.

 

[RobertP]

Bill, You're not missing anything. The two platinum salts don't mix. I'll send you Dick Sullivan's treatise on Na2 that he wrote as he was refining the method. Just don't read it if you're sleepy. Robert

 

[RobertP]

For those trying to combine Na2 with the A+B method (traditional method). Howard Efner explains what is happening on page 148 of Arentz's 2nd edition. "The platinum II salt (K2PtCl4) will exchange with the platinum IV salt ( Na2PtCl6) yielding insoluble K2PtCl6. This effectively takes the Pt IV salt (Na2) out of the solution, making it relatively unreactive." Now I'm sure it won't hurt to add Na2 to your mix if it makes you feel better but basically what you are doing is flushing platinum down the drain. Let's see.. platinum went to 2000.00/oz this week. I think I'd settle on one method or the other.

 

[clay]

This is Na2.

This is Na2 when you combine it with platinum and palladium in the same mix:

 

[Kerik]

The Turnip abides.

 

[nick mulder]

This is Na2.

This is Na2 when you combine it with platinum and palladium in the same mix:

...an extremely contrasty Pt/Pd print of a toilet

Wowsa!

 

[scootermm]

The Turnip abides.

Dead Link Removed

Stranger: I don't know about you, but I take comfort in that. It's good knowin' he's out there, the Turnip, takin' her easy for all us sinners.