Fibre RA4

[HolgaPhile]

Hi guys, sorry if this is a repeat thread, point me in the right direction please, if its the wrong forum then please move. I want to do fibre RA4 prints, is there anywhere I can get any paper from? I know Kodak use to do this and Konica were doing it until recently. Now is there any small Chinese or East German manufacturer that might have taken up the slack and are working this? I have my supplier looking into this and he recollect a Japanese manufacturer were doing it but they were recently bought up by Kodak.

 

[Claire Senft]

No such luck. I would love it also. When the EP2 chemistry was introduced to the marketplace only RC marerials were available which I believe was aimed at machine processing at higher temps.

I am not certain if the papers prior to EP were fibre based or nat. RA4 paper with a finegrained lustre surface does a reasonable job of looking like an air dried fiber paper. The print longevity is much improved.

If you must have a fiber based paper then dye transfer is in your future.

 

[HolgaPhile]

If you must have a fiber based paper then dye transfer is in your future.

Like an Epson 2000 using Hanamuhle Photo Rag? :rolleyes:

 

[Tom Kershaw]

Or possibly this:

http://www.dyetransfer.org/

 

[Paul Howell]

I have not found any digital printing system that matches dye transfer. I know that matrix film is avialable.

 

[Tom Kershaw]

Do you have any idea about how many people do Dye Transfer printing? Are there any good books or web sites?

 

[Photo Engineer]

Do you have any idea about how many people do Dye Transfer printing? Are there any good books or web sites?

Jim Browning and Ctein are two who regularly do dye transfers.

See their web sites or the dye transfer web site.

PE

 

[HolgaPhile]

Ooh, so its not a digi thing, sorry. Wow looks interesting, but looking at his website looks pretty expensive process.

So were all stuck on the fibre RA4 then? I have a chap in the UK who's looking into it, so I will get back if I find one. Just I love the texture/feel of fibre and I think I'm missing out with this on RA4. In fact RA4 seems to be dissapearing quite rapidly, wont be long befoe you can only get it on rolls

 

[David A. Goldfarb]

I know a lab owner who once ordered a custom run of fiber based RA4 paper from Kodak. He said they did it as a one time run, but wouldn't do it again.

 

[Photo Engineer]

David, I would doubt that story.

You see, with the blix process, Kodak stopped all use of FB papers for color. The Ferric EDTA tends to stain the FB paper slightly more than the old process. In addition, the baryta gives lower dye stability compared to RC/Titanox.

Kodak wanted whiter whites and better dye stability and FB paper in color stopped.

PE

 

[David A. Goldfarb]

He didn't tell me how long ago he did it, but you can ask him yourself when you're in town for your workshop. You'll certainly meet him.

 

[Claire Senft]

PE I am a bit confused. I thought that James Browning was deceased but that his wife and colleague has continued to work. Ctein expertise has been with Pan matrix film. I know that J&C is selling matrix film but is a panchromatic matrix film available?

 

[HolgaPhile]

So, PE what you're saying is that FB is unlikely on moderm papers due to BLIX staining and the Daz whiter whites desire. Hrumph Looking pretty bleak at the mo.

 

[Photo Engineer]

He didn't tell me how long ago he did it, but you can ask him yourself when you're in town for your workshop. You'll certainly meet him.

David, the last FB Kodak color paper was in the 60s. All production ceased after T-1920 paper was introduced. T-1970 and further were all RC and used the blix process.

PE

 

[Photo Engineer]

PE I am a bit confused. I thought that James Browning was deceased but that his wife and colleague has continued to work. Ctein expertise has been with Pan matrix film. I know that J&C is selling matrix film but is a panchromatic matrix film available?

EGAD! I've been speaking with a ghost on the phone then.

Jim is quite alive and well and running a huge photo shop at his business address. You may reach him through his e-mail or web site on the internet.

He does dye transfer prints from transparencies. He uses matrix film produced using the formula that he has published on the internet.

PE

 

[Photo Engineer]

So, PE what you're saying is that FB is unlikely on moderm papers due to BLIX staining and the Daz whiter whites desire. Hrumph Looking pretty bleak at the mo.

I'm saying that Kodak is unlikely to try this as the dye stability is worse, the staining is slightly higher (IIRC - this was being worked on but was abandoned due to the cessation of FB color products).

Most importantly, the formula for a FB vs an RC coating is different. Contrary to comments in another thread recently by another individual, the support change introduces a large change in the formula of a paper. RC does not absorb moisture or chemicals, but FB does and therefore there is the requirement for reformulation that goes to David's comment above. Kodak just cannot change support without reformulating, and I know that current paper is not formulated for FB support.

I have coated Ektacolor 1970 on FB and RC. They were different. This was probably the last paper ever coated on both supports unless it was 1920. This was about 1967 or so. The formulas were quite different as noted above, and ever since, FB was never used as a test bed for color papers.

Those who are not familiar with coating on different supports tend to trivialize the differences, but I assure you that there are huge variations in support based on paper types and addenda in the papers themselves. This requires reformulation. The same is true if you try to coat a Pt/Pd or Cyanotype on different papers. I've seen problems there as well.

PE

 

[Claire Senft]

Glad am I to hear Mr Browning is alive and well. Thank you for correcting my ignorance.

 

[Ryuji]

Most importantly, the formula for a FB vs an RC coating is different. Contrary to comments in another thread recently by another individual, the support change introduces a large change in the formula of a paper. RC does not absorb moisture or chemicals, but FB does and therefore there is the requirement for reformulation that goes to David's comment above. Kodak just cannot change support without reformulating, and I know that current paper is not formulated for FB support.

I have coated Ektacolor 1970 on FB and RC. They were different. This was probably the last paper ever coated on both supports unless it was 1920. This was about 1967 or so. The formulas were quite different as noted above, and ever since, FB was never used as a test bed for color papers.

Those who are not familiar with coating on different supports tend to trivialize the differences, but I assure you that there are huge variations in support based on paper types and addenda in the papers themselves. This requires reformulation. The same is true if you try to coat a Pt/Pd or Cyanotype on different papers. I've seen problems there as well.

Ron, are you distorting my postings again?

It is obvious that in color printing materials the emulsions have to be reformulated to accommodate the difference between the support materials. This is very different from the case of you coating primitive b&w emulsion on various fiber paper bases. The major difference on the emulsion side comes in the consideration of tonality, color saturation and neutrality of gray.

The scattering of light by the whitener affects the selection of suitable filtering dyes added to each layers. Also in the case of baryta there is some chemical diffusion into the base and will decrease the efficiency of coupler reaction in the lowermost layer. There are several additional considerations in the color material.

Change of the bleaching agent from ferricyanide to iron aminopolycarboxylate complex is one thing. I think this happened well before the RA-4 process.

In 1960s the color papers were still containing high molar fractions of AgBr and the order of layers may be different from the RA-4 era. Ektacolor 2001 and subsequent AgCl-based RA-4 papers also changed the stories again. The red- and green-sensitive layers are much less sensitive to blue light than before and so the blue-sensitive layer is usually coated first (botom). Thus reflection of blue light by the support is a part of the emulsion design. It's obvious that the emulsion has to be redesigned if the support material is changed.

But these are an aspect of multilayer color materials and their processing chemistry, and so they are at a completely different level from your primitive b&w emulsions.

I coat my emulsions on various fiber papers, plastic films and glass plates, all at coating speed lower than 10m/min, but difference among paper substrates is easily absorbed by applying a custom subbing layer before coating the emulsion. Even then, the role of subbing layer is concerned about mechanical strength and adhesion, and not about the emulsion property. Depending on the difference in the substrate and the whitener (among reflection materials---transparency is a different story), I see some small difference in the sensitometric curves, but that's well within what I can tolerate. Also, I can change the curve by changing the pAg of the growth stage, blending proportions, or often simply by changing the coating weight, if I really want to, but that's not necessary. I think you are overcomplicating the issue when simpler solutions are already worked out.

 

[Photo Engineer]

Two weeks ago Friday, I demonstrated my coating method for a member of the faculty, who is a conservator for George Eastman House. This was done in my darkroom here at home.

The demonstration included coating the exact same emulsion formula on two different fibre based supports. He was able to observe first hand that the coating went well on one support but repelled heavily on the other, leaving large gaping spots.

We allowed the prints to dry and had lunch together, and then went back to the darkroom and processed them so he could again observe them in the light. That next week, I brought the prints to GEH so he and I could share them with another member of the faculty and discuss this very observation. Support changes can require reformulation of a coating with respect to surfactant or require other changes to allow for a smooth coating.

Ryuji has made a statement. It may indeed be the case for him, but I object strongly to his criticizing my work and saying that I am wrong. I make no comment about his work, merely that I have had to reformulate coatings here at home and at Kodak due to support changes.

I daresay that I have probably made more hand coatings in a week than he has made in his entire life. These were both color and B&W. My formulas are and were adjusted to coat well, not to satisfy some abstract need to be identical. This is, in large part art. What works for you may not work for me and etc.... Therefore, his observations and mine may differ but that does not need an element of criticism to enter into it.

In a typical evening at home, I coat about 15 sheets of 11x14 paper with a good surface area of 8x10. I find that even going from 4x5 to 8x10 on one single paper will change the required surfactant level to get an optimum coating even with all other aspects kept constant.

Having performed this demonstration to other individuals I feel that I can rest the case. I do not call Ryuji's results into question at all. Differences exist between methodologies, paper size, temperature and etc. The also differ between emulsion types. I have learned this through years and years of experience.

Ryuji does not seem to accept the fact that things differ. He even implies that I'm in error. My results have been demonstrated for several GEH faculty members and for fellow Kodak engineers. They all are aware of similar problems in developing this art form for the darkroom enthusiast.

At the present time, a series of workshops are being conducted at GEH under a grant from Mellon Institute. GEH has purchased one of my coating blades and this blade, a prototype, was delivered last week. Next week, I hope to be showing the instructor how to use it in his course for coating prints on a variety of FB papers.

Sorry to get so far off-topic, but this continual innuendo by Ryuji that I don't know what I'm talking about is getting to me. I apologize to the readers, but I felt that this response was needed. His work is just fine, from what I have seen. I have no criticism of it. I have posted some of my prints on this site in other threads for you to judge my results as well.

PE

 

[Ryuji]

See, this is typical Ron in switching the issues and he has to be right at the end. We've seen enough of this.

Anyway, what you are talking about is coating defect, which is a mechanical issue related to spread and adhesion. A change in surfactant is not really a reformulation of emulsion. What an exeggeration!

On the other hand, the reason why the emulsion system has to be redesigned in color paper has more to do with chemical and optical properties of the substrate. That's my point in the previous post. Where did I criticize your work? What's discussed above are concerned about color material and your current work is b&w. There is nothing to criticize here, besides your fallacious reference to my post in another thread.

 

[Photo Engineer]

Ryuji;

On FB support, the support absorbs both water and soluable chemicals from the emulsion melt. On RC, the support does not.

For this reason, on RC support, hardener, salts and surfactants are present in the wet emulsion layer initially at a lower concentration than they are in the same thickness of emulsion coated on FB support. The water and soluable materials are effectively 'sucked' out into the FB support as the emulsion layer thins down due to moisture loss. The water and smaller ions will diffuse out more rapidly than some of the larger organic or ionic species.

In the former case, the effective ionic strength and the pAg are different than in the latter case. We really cannot measure the effective redistribution of chemistry into the FB, we just know it is different. It is related to rates of absorption of the moisture relative to the other chemistry by the FB in the moments after coating.

Therefore, all consitiuents in the melted emulsion, prior to coating may have to be adjusted before high quality coatings can be made on these two supports. It depends on the emulsion and the FB paper. Among the varieties of FB paper, it also depends on surface and degree of calendering as well as whether barium sulfate or barium oxide are used (pH for example may be quite different), and what level and type of gelatin, humectant and hardener were used in the barium layer. RC is more uniform in this regard, of course.

After coating, on drydown, the emulsions have different keeping properties and sensitometric properties unless these adjustments are taken into account by other changes. This is because the water soluable chemicals are evenly distributed in the FB paper as a function of the depth of penetration of the water as coated, but on RC support, all ionic species remain in the surface layers.

This has great impact on my 'primitive' emulsions, having tested them on a variety of FB and RC supports. It also has impact on larger scale production.

Reequillibration of chemsitry in FB papers is what often causes FB papers to keep more poorly than RC papers. With RC papers, the exact final chemical balance can be ajusted rather precisely, whereas in FB papers it is continually changing.

The remarks on color paper regarding optical properties that you made are, for the most part, incorrect. All negative color papers had the yellow layer on the bottom since before 1960. The reason is due to the required photographic speed of the yellow (blue sensitive) layer relative to the other layers and dye stability, not optics.

PE

 

[Ryuji]

The remarks on color paper regarding optical properties that you made are, for the most part, incorrect. All negative color papers had the yellow layer on the bottom since before 1960. The reason is due to the required photographic speed of the yellow (blue sensitive) layer relative to the other layers and dye stability, not optics.

In old color paper material, red- and green-sensitive emulsions had rather high blue sensitivity, and therefore they had to be placed below blue-sensitive (cyan-forming) layer and a blue-absorbing yellow filtering layer.

In more modern papers, residual blue sensitivity of red- and green-sensitive emulsions is low enough to remove the yellow filter and shuffle around the layers.

I've checked these at least for the case of Fuji paper products.

 

[Ryuji]

For this reason, on RC support, hardener, salts and surfactants are present in the wet emulsion layer initially at a lower concentration than they are in the same thickness of emulsion coated on FB support. The water and soluable materials are effectively 'sucked' out into the FB support as the emulsion layer thins down due to moisture loss. The water and smaller ions will diffuse out more rapidly than some of the larger organic or ionic species.

In the former case, the effective ionic strength and the pAg are different than in the latter case. We really cannot measure the effective redistribution of chemistry into the FB, we just know it is different. It is related to rates of absorption of the moisture relative to the other chemistry by the FB in the moments after coating.

Therefore, all consitiuents in the melted emulsion, prior to coating may have to be adjusted before high quality coatings can be made on these two supports. It depends on the emulsion and the FB paper. Among the varieties of FB paper, it also depends on surface and degree of calendering as well as whether barium sulfate or barium oxide are used (pH for example may be quite different), and what level and type of gelatin, humectant and hardener were used in the barium layer. RC is more uniform in this regard, of course.

I agree with some of what you said above, but I don't agree that those factors are strongly related to coating defects you mentioned in the other thread. Plus, in the other thread you didn't discuss RC, only baryta and non-baryta fiber papers. So my previous comments apply only to baryta and non-baryta fiber papers and not RC. I coat on plastic films and glass plates, and so I know there is some difference there, but not as drastic as you described. What I do is to use a synthetic polymer blend that increases adhesion between the gelatin macromolecules and the substrate, and use different hardeners depending on the polymer blend (so that the synthetic polymer, the modified gelatin, and raw gelatin are crosslinked each other). I don't consider this to be a reformulation of the emulsion. Nucleation, ripening, growth, desalting, digestion, stabilization, and spectral sensitization are identical. Just different addenda.

 

[Photo Engineer]

I repeat, since the time that Kodak began using a color mask, NO Kodak negative color paper had the yellow layer on top. This well predates the 60s. That is why the color paper has a cyanish cast when wet, due to the cyan layer being on top. Of course, this cyanish cast is greatly reduced in the modern papers but was quite strong in the early papers.

Agfa color paper did have the yellow layer on top until they began using masked color negatives, and the same is true of Fuji and Konishiroku. This took place for these companies sometime in the 60s. It is also the time when they converted from the water soluable Fischer couplers to the Kodak oil soluable couplers.

PE

 

[Photo Engineer]

I agree with some of what you said above, but I don't agree that those factors are strongly related to coating defects you mentioned in the other thread. Plus, in the other thread you didn't discuss RC, only baryta and non-baryta fiber papers. So my previous comments apply only to baryta and non-baryta fiber papers and not RC. I coat on plastic films and glass plates, and so I know there is some difference there, but not as drastic as you described. What I do is to use a synthetic polymer blend that increases adhesion between the gelatin macromolecules and the substrate, and use different hardeners depending on the polymer blend (so that the synthetic polymer, the modified gelatin, and raw gelatin are crosslinked each other). I don't consider this to be a reformulation of the emulsion. Nucleation, ripening, growth, desalting, digestion, stabilization, and spectral sensitization are identical. Just different addenda.

I am trying to include all of the papers that I have coated on, and all of the results that I have seen.

I include in the emulsion formulation the stabilization step as you do.

Therefore, if a change in the level of stabilzer is needed, it is a change in the emulsion formula. In the case of RC or film, a given dry emulsion layer 'sees' more stabilzer than 'seen' by the same thickness of emulsion coated on plain paper or baryta paper and therefore the results are different. The stabilzer has equillibrated within both the emulsion and the paper stock in the case of any FB paper. It has not in the case of RC or film support.

This usually would be seen as a slightly higher speed on a FB support with worse keeping over time everything else being equal.

PE