New rod coating problem (to me) for 7x17 Pt/Pd print

[Andrew Keedle]

Hey, I rod coated a 7x17 Pt/Pd print with 24+24+6 drops which seemed to cover really well. After drying for a short while in a dark box this pattern appeared. I heat dried it and printed it anyway and the white spots/mottling appeared. I'm assuming too much emulsion and the paper got too wet, maybe too many passes as I had excess liquid and this dragged/damaged the fibres. Any other suggestions? Thanks in advance.

 

[Mainecoonmaniac]

As for me, I find if the coating is uneven, it will buckle. Are you coating your paper with newspaper under it on top of a piece of glass? Also, If there's excess, don't try to coat your paper with any left over emulsion. I push the puddle over the paper once then absorb the rest with a paper towel. Make sure the puddle is even across the glass rod. Capillary action should draw the emulsion across the rod evenly. I find bigger sheets of paper buckles more than small sheets.

 

[jim10219]

You've got a near perfect rectangle in the middle of that paper where the emulsion didn't adhere. Do they all look like this? Because that's weird. Usually, coating problems from glass rods show up as long streaks. The shape of that makes me think there's something else going on. Perhaps there's something wrong with the paper, or the surface below the paper. Or it could be just a fluke. It's hard to say if it just happened once. But I have never experienced a problem while coating paper with a rod that looked anything like that.

 

[Andrew Keedle]

As for me, I find if the coating is uneven, it will buckle. Are you coating your paper with newspaper under it on top of a piece of glass? Also, If there's excess, don't try to coat your paper with any left over emulsion. I push the puddle over the paper once then absorb the rest with a paper towel. Make sure the puddle is even across the glass rod. Capillary action should draw the emulsion across the rod evenly. I find bigger sheets of paper buckles more than small sheets.

Just once. What little coating I’ve done had been with a brush but that wastes too much emulsion. This was on a piece of newspaper on a work surface. I will try a piece of glass, less liquid and fewer passes. Thanks.

 

[Andrew Keedle]

You've got a near perfect rectangle in the middle of that paper where the emulsion didn't adhere. Do they all look like this? Because that's weird. Usually, coating problems from glass rods show up as long streaks. The shape of that makes me think there's something else going on. Perhaps there's something wrong with the paper, or the surface below the paper. Or it could be just a fluke. It's hard to say if it just happened once. But I have never experienced a problem while coating paper with a rod that looked anything like that.

Yeah the symmetry is really odd. It is possible it’s the paper. It’s Arches Platine that’s been sitting around for 12 years. I haven’t had any similar issues with other sheets from the same stash. I think maybe too much liquid and too much pushing and just a fluke with the shake. ‍ Thanks.

 

[Alan9940]

I've never seen anything that large, but I have had small marks that look like that and it was the paper. And, yes, I've had and not had the issue within the same pack of paper. I never figured out what causes the issue; I simply make another print.

 

[Andrew O'Neill]

I coat paper on glass. I only use heavy weight paper such as Hahnemuhle PR as they lay nice and flat. I use a bit more sensitiser than needed. I always make four passes, then Q-tip up the excess. I find if I skimp on solution, I run into issues. You're making Pt/Pd, so you certainly don't want to have too much excess...unless you're filthy rich. My experience is with kallitypes, and cyanotypes, so not too concerned about the excess... (thank God carbon transfer is so cheap!)

What paper are you using? Maybe you should practice with something cheap and easy like cyanotypes...

 

[Mainecoonmaniac]

Just once. What little coating I’ve done had been with a brush but that wastes too much emulsion. This was on a piece of newspaper on a work surface. I will try a piece of glass, less liquid and fewer passes. Thanks.

Good luck with the glass. Brushes can use more emulsion. Pt is expensive. But I've used this brush with great success. The trick is to wet this brush and use a paper towel to soak up as much water out of it then pour the pre-measured emulsion on the paper then brush evenly and quickly. If gives a nice edge too.
https://www.jerrysartarama.com/rich...OuhSv649yoCWkhOLyFVKLn0hurDpM3ooaAkdLEALw_wcB

 

[Andrew Keedle]

Good luck with the glass. Brushes can use more emulsion. Pt is expensive. But I've used this brush with great success. The trick is to wet this brush and use a paper towel to soak up as much water out of it then pour the pre-measured emulsion on the paper then brush evenly and quickly. If gives a nice edge too.
https://www.jerrysartarama.com/rich...OuhSv649yoCWkhOLyFVKLn0hurDpM3ooaAkdLEALw_wcB

Oh thanks! I was wondering about a synthetic brush rather than a Jaiban Goats hair brushes. I'll see if I can find something similar in the UK. Thank you.

 

[Andrew Keedle]

I coat paper on glass. I only use heavy weight paper such as Hahnemuhle PR as they lay nice and flat. I use a bit more sensitiser than needed. I always make four passes, then Q-tip up the excess. I find if I skimp on solution, I run into issues. You're making Pt/Pd, so you certainly don't want to have too much excess...unless you're filthy rich. My experience is with kallitypes, and cyanotypes, so not too concerned about the excess... (thank God carbon transfer is so cheap!)

What paper are you using? Maybe you should practice with something cheap and easy like cyanotypes...

Ha, definitely not filthy rich. The cost is one of the things that makes it difficult to experiment too much! I'm using some old Arches Platine, might get some new paper to test out. Thanks.

 

[Mainecoonmaniac]

I coat paper on glass. I only use heavy weight paper such as Hahnemuhle PR as they lay nice and flat. I use a bit more sensitiser than needed. I always make four passes, then Q-tip up the excess. I find if I skimp on solution, I run into issues. You're making Pt/Pd, so you certainly don't want to have too much excess...unless you're filthy rich. My experience is with kallitypes, and cyanotypes, so not too concerned about the excess... (thank God carbon transfer is so cheap!)

What paper are you using? Maybe you should practice with something cheap and easy like cyanotypes...

You're right in practicing on cheaper processes like cyanotypes. I just starting to experimenting with Kalitypes because it's so much cheaper. There are more steps involved as you know. But from what I've heard and seen, a good Kalitype is indistinguishable from a planotype.

 

[Andrew O'Neill]

Ha, definitely not filthy rich. The cost is one of the things that makes it difficult to experiment too much! I'm using some old Arches Platine, might get some new paper to test out. Thanks.

Arches Platine is one of the most beautiful papers out there. I was using it until the infamous bad batch appeared. I still have a few sheets of the bad stuff, and use it for carbon transfer. Works beautifully. You'll know if you have the bad stuff, when you soak a piece in water and it turns all spotty. Your paper looks fine, though.

 

[jeffreyg]

I use Arches Platine from Bostick and Sullivan. The package indicates which side of the paper to coat. I brush the paper with distilled water first and coat when the wet paper has almost dried. I have used puddle pushers but prefer a sable brush with the paper on an acrylic sheet. I let the coated paper air dry then further dry from both sides with a blow dryer.

http://www.jeffreyglasser.com/

http://www.sculptureandphotography.com/

 

[CasperMarly]

Years back was at a workshop with Dick Sullivan and he was using the glass puddle pusher to coat the papers. He emphasized "Two Passes" only. Down and back twice. Said doing more would cause problems with the paper surface. Also that the weight of the glass on the surface of the paper was enough to do it right so we did not to put any extra pressure on it. Watching him coat the paper and then doing it ourselves with him and other excellent Pt/Pd printers helping apparently short cut a lot of the problems we might have had otherwise.
Another good Pt/Pd printer showed and guides us with brush coating so we saw two methods and got to practice with both.

One thing brought out was "flat,hard surface" as any paper or cloth or such under our coated sheet could cause problems.

Don't know just what caused your pattern but maybe some practice on normal paper with water containing a few drops of food dye or watercolors to practice coating? I did that for awhile to assure myself I could get things on without streaking. I think it worked, but more likely just gave me confidence before committing to the costly metal salts.

 

[TheFlyingCamera]

I've done both rod and brush coating. I greatly prefer the brush. Definitely get a synthetic bristle brush, like a Richeson 9010 (aka the "magic brush") or one of the Japanese brushes like this: https://shop.inkjetmall.com/Kobayas...Inch.html?category=183#attr=36014,16092,50001 the Kobayashi synthetic. They have multiple sizes of these brushes. The reason I like them more than the Richeson is there is no metal anywhere on the brush, so nothing that can rust/corrode over time and contaminate the bristles. You can order them from Japan directly and save some money on the price of the brush, but it doesn't make a whole lot of sense unless you buy multiples to save on the shipping cost.

Definitely, do your coating on a hard, smooth surface directly below the paper, like a sheet of plexi or glass, or even just a melamine countertop (or the baseboard of your enlarger, as I have to - not enough space in my darkroom for dedicated counter space). I suspect that having newsprint under your paper may have contributed to your coating issue by absorbing moisture away from your printing paper.

 

[Mainecoonmaniac]

I use both Richeson 9010 brush and a glass rod. The brush had more control and the rod is more economical. I only use my Richeson 9010 with Ziatype only. The I use my glass rods for Ziatypes, cyanotypes and salt prints. I worry about cross contamination with brushes.

 

[Fraunhofer]

Good luck with the glass. Brushes can use more emulsion. Pt is expensive. But I've used this brush with great success. The trick is to wet this brush and use a paper towel to soak up as much water out of it then pour the pre-measured emulsion on the paper then brush evenly and quickly. If gives a nice edge too.
https://www.jerrysartarama.com/rich...OuhSv649yoCWkhOLyFVKLn0hurDpM3ooaAkdLEALw_wcB

I do the same and find this a lot easier than the glass rod. I have a brush for each process, so no cross contamination. When the brush is pre-wetted it seems not much worse than a glass rod economy-wise.

 

[Mainecoonmaniac]

I do the same and find this a lot easier than the glass rod. I have a brush for each process, so no cross contamination. When the brush is pre-wetted it seems not much worse than a glass rod economy-wise.

Economy for me is especially important with process that use platinum and palladium. I find there's not a huge difference also. I also prewet my Richeson 9010 brush then I use a folded paper towel to dry as much water off the brush making a sharp edge. The edge of a brush is more like a squeegee pushing the emulsion on the paper like a glass rod.

 

[Andrew Keedle]

Thanks for all the comments and suggestions about coating. I think some kind of synthetic brush might be a good shout to try.
I did find out what caused the issue I described in the initial post. I use a shallow print box (as it's the only one I have big enough) to store the paper whilst it's drying. With the curl induced by coating it touched the underside of the lid thus losing emulsion... Nothing wrong with my coating, nothing wrong with the paper. Just dumb stupid user error...

 

[CasperMarly]

Thanks for all the comments and suggestions about coating. I think some kind of synthetic brush might be a good shout to try.
I did find out what caused the issue I described in the initial post. I use a shallow print box (as it's the only one I have big enough) to store the paper whilst it's drying. With the curl induced by coating it touched the underside of the lid thus losing emulsion... Nothing wrong with my coating, nothing wrong with the paper. Just dumb stupid user error...

View attachment 264959

There are good reasons Claymore Mines have "FRONT TOWARDS ENEMY" in big, raised letters on them.