Rod-coating Ruscombe's Herschel

[IanFoster]

Ladies and Gentlemen,

I'm attempting to produce Pt/Pd prints using B&S chemistry with the Herschel linen paper from Ruscombe, but I'm struggling with buckling.

With Arches Platine 1 drop of sensitizer covered around 2.5 square inches, so 20 would be fine for an 8x6 and that's what I've been trying. You know when the tide goes out and you get that lovely rippled effect on the sand as it dries out? That's what my paper ends up looking like, so when I stick it in my homemade vacuum press for a 6.25 minute exposure I get out of focus areas the size and shape of my finger across the print.

I'm getting this even when I tape the paper on all 4 sides before coating, so my next experiment was going to be to pre-soak the paper in warm water and then gum/tape it to some aluminium, let it dry, then try coating it.

The thing is, enough people have recommended Herschel online without mentioning the issue I'm getting for me to think I'm missing some fundementally obvious point and I should prepare my soul for some royal abuse for posting my woes.

Any guidance - spiritual or otherwise - would be most appreciated.

Ian.

 

[Loris Medici]

Ian, a couple of questions:

1. What's the temperature and relative humidity of your darkroom / paper storage? (Too dry is no good for coating paper...)
2. Have you tried brush coating? (Just to see if you get something different...)
3. Do you use any surfactant? (Tween, Ilfotol or similar...)

BTW, 20 drops per 8x6 sounds like too little solution to me; my usual is 0.25ml coating solution per 10 sq. in. coating area and it works great with many different papers... (8 x 6 / 10 x 0.25 = 1.2ml, 1.2ml x ~25drops per ml = 30 drops vs your 20 drops!)

P.S. I have no experience with Herschel paper, but since Mike Ware recommends it (see (there was a url link here which no longer exists)) it should be a very very good paper.

 

[jeffreyg]

I also have no experience with that paper. Perhaps double coating from the other direction (first from the long direction ... second coating from the short direction) will help. I don't double coat but I understand some do routinely. Also maybe a more dilute solution by adding a few drops of distilled water will do a better job. I use Arches Paltine with a puddle pusher and add distilled water to my emulsion mix and find coating to be easy.

http://www.jeffreyglasser.com/

 

[TheFlyingCamera]

That definitely SOUNDS like a humidity issue - the paper is pulling a lot of moisture out of the emulsion and buckling as a result. Have you tried just pre-humidifying with steam, either from an open tray or over an electric kettle? I do that in my darkroom in the wintertime when the humidity can drop quite low.

 

[IanFoster]

Hi all,

Many thanks for applying yourselves to this one, I'm very grateful.

To Loris:
Temperature is 18-22C, RH 40-50% which from what I've read is within normal limits.
I've not tried brush coating yet - I'll give it a try at some point but my gut says unless I can get an even more even coating then the effect may be worse.
I put one drop of Tween into 2cc of distilled water and after a little shaking - the water, not me - I draw a single drop to add to the 20 drops of sensitizer for an 8x6. I reckon that's very roughly 800:1, Dr Ware recommends 0.1-0.2%, so that's as far as I've got exploring that variable.
Very interested that you've approximated 25 drops/cc when I've always thought it was 20 drops. Not sure whether that's going to be the difference that makes the difference, but I can experiment with that too.
To Jeffrey and the Flying Camera: Loved the picture of the boat on page 4 btw - yup, I'm with you. Once I got started I didn't have any problems with Platine either. While I've never attempted double coating, Herschel is an extremely light paper in comparison to Platine so I probably would start my experiments with the $5/sheet option.
I'm interested in the thought about pre-humidifying the paper. The paper is made from linen rather than cotton, it's not pressed in the same was as the Platine and it's about 2/3 the weight so there are a number of differences. It almost feels as though it's been retrieved from a tomb. It's hard to convey but the lightness and thin-ness (?) of the paper almost suggests a prehistoric dryness and humidity that's far lower than that of the room in which it's been stored.

Many thanks all. The next action for me is to try pre-humidifying the stuff, probably over a tray of warm (40-50C) water - what's the concensus(sp): 3-5 minutes?

I'll let you know how I get along,

Ian.

 

[Loris Medici]

...Very interested that you've approximated 25 drops/cc when I've always thought it was 20 drops. Not sure whether that's going to be the difference that makes the difference, but I can experiment with that too...

Well, that highly depends on the density / surface tension of the solution and to the size of the dropper's mouth actually, therefore always tell the ml volume of the sensitizer...

Edit: Try to humidify the paper until it feels limp / snappy...

Let us know how it goes!

Good luck,
Loris.

 

[davido]

Ian,

My Herschel arrived on the weekend and I made my first test print today.
It is a thin paper and it does buckle after coating, but I didn't find that a problem.
As it is so thin, I can't see how it would be problematic once it's pressed in a frame or vacuum frame?
I have a Nuarc 26-1K and my print came out perfectly sharp.

This paper is beautiful! I think I'm going to get hooked. After years of battling with staining with other papers (even Platine), Herschel comes out with clear high lights and the Dmax is stunning!
This paper is incredibly absorbent! I used 15 drops plus one drop of Everclear (instead of Tween) for an area of about 8 x 4. I also humidify the paper for at least a few hours in my coating area at 60% humidity. I let the paper dry for 30 minutes in that humidity before printing.

I should also point out that I am now doing Argyrotype printing. This paper was recommended for this process.

Perhaps you're drying the paper too long? Or, more likely, your vacuum frame is not strong enough?

cheers
david