double-coating pt/pd

[TheFlyingCamera]

I did my first double-coated pt/pd print today. I had an image that really begs for the cool platinum image tone much more than the warm palladium, so I first tried a pure platinum print. That was a failure - really underexposed (my fault) and it looked really thin - I'm guessing too low a drop count. Re-did it with an 80/20 Platinum/Palladium mix and a higher total volume of solution. Better, got the exposure about right, but the contrast was still off. So I decided to try a double-coated print, as it's supposed to yield better contrast. It definitely worked. I was able to see far more detail in my shadows than I was before, and the blacks are snappier. Now the decision is, is it worth it?

[keithwms]

In my estimation no, it wasn't worth it for me, although maybe when I see your print I'll think otherwise! Anyway, maybe once I get over my move and unpack my roomful of boxes of photo stuff I'll get back to the project of adapting an inkjet to apply Pt/Pd solutions. Then multilayering might be reasonably economical.

I've read about applying gum over platinum for better depth, have you tried that yet? I applied sandarac varnish and that helped a fair amount.

[phaedrus]

Anyway, maybe once I get over my move and unpack my roomful of boxes of photo stuff I'll get back to the project of adapting an inkjet to apply Pt/Pd solutions.

Not to diminish or discourage your efforts, but would that work even theoretically? Has it been done? Aren't the print head's orifices metallic and heated? Wouldn't they clog with metallic Pt and Pd right away?

[Ian Leake]

Congratulations Scott. Double coating can be a PITA and the difficulty / benefit depends on the paper, but when you've found a way that works it can really lift a print.

Was it worth it? That depends on whether the print looks better than when single coated. I've made double coated prints which zing from across the room, and others which are not much different from a heavy single coat.

Enjoy the new tool in your tool bag.

[donbga]

Anyway, maybe once I get over my move and unpack my roomful of boxes of photo stuff I'll get back to the project of adapting an inkjet to apply Pt/Pd solutions.

Yeah right. That will be the day that frogs can fly.

[donbga]

so I first tried a pure platinum print. That was a failure - really underexposed (my fault) and it looked really thin - I'm guessing too low a drop count. Re-did it with an 80/20 Platinum/Palladium mix and a higher total volume of solution. Better, got the exposure about right, but the contrast was still off. So I decided to try a double-coated print, as it's supposed to yield better contrast. It definitely worked. I was able to see far more detail in my shadows than I was before, and the blacks are snappier. Now the decision is, is it worth it?

Have you tried printing pure platinum prints that are brush developed in glycerin and potassium oxalate? This procedure is described in Sullivan & Weese's New Platinum Print. The method works very well. However it's a bit too expensive for my wallet, I've only made 3 pure platinum prints with that technique.

[Ian Leake]

Have you tried printing pure platinum prints that are brush developed in glycerin and potassium oxalate? This procedure is described in Sullivan & Weese's New Platinum Print. The method works very well. However it's a bit too expensive for my wallet, I've only made 3 pure platinum prints with that technique.

From your description this sounds like how the early platinotype printers used to control contrast. Developer temperature effects development time. By using a cool developer with glycerin on the print and in the developer they could really slow down the development time which allowed them to control local contrast with a brush. It's very effective, although for most purposes it's easier to use a dash of potassium dichromate coupled with some judicious dodging and burning.

[TheFlyingCamera]

The double-coat in this case was definitely effective at snapping up the Dmax and improving mid-tone contrast, at the sacrifice of my highlights. All I need to do in this case now is to bring the highlights up back to near-white. I tried doing a pure platinum print but that didn't work very well - I used the same drop count I would have used for a palladium, and at the same time as my palladium print, it looked like it was about 2 stops underexposed and needed about double the coating solution - you could see brush marks in the image area. I'm using Bergger COT320 for my paper so I doubt it's a paper issue.

[Ian Leake]

COT320 isn't a good paper for pure platinum prints. The gelatin sizing binds to the potassium chloroplatinite and hinders the chain of reactions which forms the image. Try printing on the reverse side where there's no gelatin. As far as I'm aware there's only one paper which works for a pure platinum image 'out of the box' and that's Buxton.

[Davec101]

I did my first double-coated pt/pd print today. I had an image that really begs for the cool platinum image tone much more than the warm palladium, so I first tried a pure platinum print. That was a failure - really underexposed (my fault) and it looked really thin - I'm guessing too low a drop count. Re-did it with an 80/20 Platinum/Palladium mix and a higher total volume of solution. Better, got the exposure about right, but the contrast was still off. So I decided to try a double-coated print, as it's supposed to yield better contrast. It definitely worked. I was able to see far more detail in my shadows than I was before, and the blacks are snappier. Now the decision is, is it worth it?

Did you take a density reading of the double coated print? We have been discussing related issues over at the hybrid forum at length, here : http://www.hybridphoto.com/forums/showthread.php?t=2047

I will be testing Penn's method of double coating on sheets of paper bonded to aluminium in the next couple of weeks to see if their is a significant difference using a platinum/palladium mix.