Grain in Platinum Printing

[Natha Congdon]

(Warning: Long-winded thread only of interest to obsessive alt photo types!)

I've been printing Pt/Pd for about a year, mostly 12X20 negs (HP5+/pyro) on plat inotype paper, and feel like I'm getting pretty good control of the basics now, except for one painful and (to date largely unavoidable)fly in the ointment. My test strips, usually printed at about 8X10 or so, almost always seem to have a s moothness that I can get only intermittently in the full 12X20s. I use the same paper (although the 11X14 version) for the test strips, and have been through se veral batches of paper and several seasons of weather here in Baltimore with abo ut the same results. The 12X20s look a bit grainy, with the grain often looking slightly dark, at the extreme almost like the print was dirty from being stepped on (usually it's more subtle, but side by side against the test strips, no ques tion at all that the difference is there.)

Hypotheses explored and rejected:

1. Chemicals too cold. I've heated them gently in a water bath, even kept them w arm for several minutes to make sure that whatever is supposed to happen when th e chemicals get above 70F has time to happen. My workspace never gets below 65F. I warm the coating rod, paper and work surface as well as the chemicals.

2. Too much restrainer. Rarely use much at all, never as much as a 1:1 ratio, us ually more like 5:1 FeOx to FeOx with restrainer.

3. Too rough on the paper. I've gotten to the point, I think, of being really qu ite light with the rod, certainly no rougher on the 12X20 than the 8X10 (I'm an eye surgeon, so I think I've got a pretty light touch!)

4. Have been printing with pure Pd, which does seem to help a bit, but not elimi nate the problem.

5. Something in the developer. Use the same for the test strips and full-size pr ints, and have noticed the prob with Sullivan cold bath, K oxalate and citrate d evelopers.

6. Since I don't usually wash test strips for a full 20 min, I thought maybe too long a wash was roughing up the surface of the paper. No dice: a shorter wash t ime on a trial basis didn't help.

Hypotheses not yet tested, but would prefer to avoid Sysiphean agony of it all:

1. Reduce the proportion of FeOx to metal salts (recommended in the Sullivan/Wee se book I think, or is it Arentz?)

2. Use a 21 inch rod to coat 12X20 the long way (Carl Weese suggests this I thin k, specifically to go "with the grain" on Platinotype paper. Don't ask me!)

3. THe graininess is coming from too much metal salt, might be helped if I mask the borders or even reduced my volume of coating (I use 8 ml for 12X20, almost e xactly 3X what I use for my 8X10 test strips.)

4. Something fiddly about the ORDER in which one mixes the FeOx and metal salts, suggested by Nadeau.

ANY suggestion to help with this extremely vexing problem would be greatly appre ciated, especially if it requires obsessive attention to some detailed little "l ucky" ritual, the purpose of which is only vaguely understood!

Who needs Prozac for obsessive-compulsive disorder when you can treat it so much more expensively and satisfactorily with Platinum salts!

Thanks in advance,

"Bewildered in Baltimore" (Nathan Congdon)

[Jorge Gasteazoro]

Nathan the only two things I can suggest is a negative with too much contrast forcing you to use solution #1 or metal contamination of your coating solution. Hope this helped.

[William Marderness]

I would try the "go with the grain" idea by using a longer rod. You could try coating an 8x10 against the grain to see if that is a problem. Are you using the same side of the paper with the 8x10's and 12x20's?

[Mark Nowaczynski]

When I first started making platinum prints it was January in Toronto and the indoor air was extremely dry. My prints suffered from a similar graining problem. Two months later I moved into a proper facility which was temperature and humidity controlled. I always coated and printed in 50-60% relative humidity at 72-74 degrees. Individual sheets of uncoated paper (Crane's) sat overnight on screens in this environment. Coated paper self dried on a screen mesh for one hour prior to exposure, I never used a hair dryer etc. My sensitizer solution did use 1/3 Pt, 2/3 Pd and a small amount of restrainer. Developer solution (K Oxalate) was always heated to 100 degrees. I now have lovely grain free 16X20 platinum prints to show for it (made from 4X5 originals enlarged to 16X20). Good luck!

[clay harmon]

One friend of mine solved a graininess problem with fresh potassium oxalate developer. That said, i would be willing to bet that it may be the #2 solution you're using for contrast control or your coating rod. You might try using the B&S Na2 diluted to 25% of original strength for contrast control. It seems to cause less graining. You also might try the Richeson 9010 brush for coating. It is very smooth and uses about the same amount of solution as a coating road. You get the brush soaking wet in distilled water, give it 4-6 shakes and pour and brush until all the solution is in. It is in my opinion the best brush by far and beats a coating rod hands down. Artxpress.com has them for sale on then web. Another thing is staying away from forced air heat drying with a blow dryer - try an old window fan and no heat. Hope one of these suggestions help.

Clay

[Michael Mutmansky]

Nathan,

Are you getting any 'wash off' of the coating in the developer, or any density migration on the print?

If you have too much or too little sensitizer on/in the paper, you will get some unsatisfactory results. Too much, and it will dry on top, and then wash off in the developer, resultig in a muddy appearence in the dark areas. Too little, and the print looks anemic, and never really gets to the density it should.

One suggestion that may work for you is to coat initally with the rod, but only a few passes. Then switch to a brush, and brush the entire print (*very* lightly!) until there is no surface liquid left, that is, until all the chemicals are absorbed into the fibers. Since I started doing that process, I get more consistant prints than I was before. This is similar to the approach that Dick Sullivan recommends for Platine.

I get the feeling that your problem has to do with the process, not the materials, with the one possible exception being the paper. I have had very good batches of paper, and I have had horrible batches of paper. I even got one batch that was good for part, and bad for part, all from the same order. Just because you may have ordeded several times from your paper source, doesn't mean that they didn't come from the same pallet of paper at your source.

For the paper, take some of the large paper, cut it down, and do your 8x10 tests on it. You may find that the paper is the source of the problem. Also, verify that the paper is all oriented the same way, so you aren't printing on the reverse.

If you had bad FO, then you would probably see a general fog in the unexposed areas (at the edges, or where the image is masked). This would also show up on your test prints, so that is probably not the case.

I have never paid attention to the order of the chemicals, but then I always go A-B-Cpt-Cpd just to make sure that I don't forget or double up on one.

If none of this works, then you probably have a bad interaction between your camera and the Nuarc unit; they should both be sent to me immediately for disposal!

---Michael

[Carl Weese]

Nathan,

First thing I'd do is try another paper (Platine, Lenox, Stonehenge, just something different) and see if the test strips and full size prints are different. Certainly buy large sheets of paper and cut them to the various sizes you use to stay with the same batch.

Try coating with a high quality artificial fiber brush (Richeson makes excellent ones). These don't absorb the sensitizer and so coat almost as efficiently as a rod, with the control advantages of a brush.

It seems quite likely that you are abrading the paper trying to coat it with a rod at large size, while getting a better coating on the small tests.

Try coating a full size sheet and cutting it into test strips, then see if it matches the full-size print--if it is grainy like your large prints, then the problem is in your coating technique.

[Greg Nelson]

I'm a novice, but seem to have solved a similar problem I was having. Paper type is an important variable, but I've found that graininess is a big problem IF I - Let the wet emulsion soak into the paper longer that 2 minutes before drying with a hair dryer, OR - Fail to make sure my paper and emulsion is COMPLETELY DRIED before exposing. I hate standing there several minutes waving that dang hair dryer over the front and back sides. But if I go twice as long as I think I need to, the results are rarely disappointing.

[Eric_2840]

I just printed my first Pt/Pd test strips and print last night. Same problem with the grain. Seeing these answers gives me some directions on which variables I need to look at next.

My first print was with Cranes platinotype, 3Parts a/ 3parts b/ 6parts Pt/Pd mixture (1:1 with Pt/Pd). I kept the coating solutions heated, but didn't even think about heating the coating rod. I also did not pay any attention to humidity prior to coating.

This is a great website.

Nathan, I think you are right about the Platinum salts. I don't think I'll need to get that Prozac order filled after all:-)