Making Commercial Color Separation Negatives of Transparencies for the Kodak Dye Transfer Process

[IB Photochemistry]

Color Separation negatives of color transparencies are primarily of interest to those making Dye TransferTM or dye imbibition transfer color prints, but can also be used for printing transparencies on RA-4 materials, color pigment processes, archiving images, and more. They can even be of interest to those interested in making black and white internegatives of color transparencies and other fields areas such as making color corrected duplicates and internegatives on chromogenic films.

While there are a number of procedures for making color separations in the published literature, none were used in the industry to commercially produce dye transfers, as those were inadequate. Methods used to make color separations by professional dye transfer labs were regarded as trade secrets and jealousy and selfishly guarded, but I have found many of the systems used in the industry were remarkably similar. Since there may be some interest in techniques once used to make dye transfers commercially, I think I should post an internal manual I have obtained used by Frog Prince & Company inc. to make the color separation negatives they used to make prints. The manual is from 1985 and used Kodak Super XX pan film. This was used until they bought a Versamat processor to make separations using Kodak Separation Negative films. I have attached the copy of the shop manual below. I think it would be of value to the community to openly discuss these techniques for making commercial quality separations and Kodak DT prints, as this is largely an area void of historic documentation.

I'm sure there will be some questions about this so please ask and I will try to answer. I don't have the lab's specific aimpoints for making matrices, and some information may be specific to their setup. The main DT operator at Frog Prince, Tom Rankin has been deceased for more than 25 years. This came from someone affiliated with the lab who has allowed me to publish it here.

In the manual there is a kind of mask they call a “mid-range” mask. Its really the same as a long scale highlight mask and produced in the same way. Basically its a low contrast highlight mask developed in HC-110 Dil. E, with low density (<0.60 DU) and is made by exposing though the principle masks, just like making the separation negatives with the transparency. The “mid-range” is used as a post mask while exposing the matrix with the separation negative, and does not receive more than 60% of the full exposure time as the separation negative does.

The “mid-range” has effect on the midtone and highlight areas. From my research this is also called a Long Scale Highlight mask or Long Range Highlight mask. Its function is to maintain spacial modulation in the principle mask; this expands the range of the mask and eliminates halation flair. This is necessary because you don't want halation flair from the principle masks in your images. Many books speak of using alternative films for making principle masks with an antihalation layer (without diffusion), however this was not used commercially because the diffusion of the mask improves spacial modulation of the separations. This kind of mask was made with every set at Frog Prince.

The highlight mask is made from Kodalith Pan (some labs used Agfa Litex P911P instead) and developed in D-19 1:2 for 2½ min. It is used as a post mask and receives at least 50% of the exposure that the separation negatives does. Highlight masks are needed with color transparencies because the product of the matrix toe (and dye system), and toe on the transparency have an effect of reducing contrast in the highlights, producing flat highlights. The highlight mask has the effect of raising the contrast of the highlights to preserve highlight detail.

There is a highlight pre-mask in the manual. I don't know if they used this very often. I also don't know if they added this mask back with the principle mask to to restore its curve to a more flat and linear curve. Otherwise highlights and upper midtones would have a crossover.

Usually a specular mask is made with the highlight mask and is used as a post mask when exposing the matrices. It would be less than 25% of the total exposure time with the separation negatives. The manual stops on page 29, but its possible some additional pages are missing. I think most labs used at least one of these masks with a set. Specular highlight detail can be lost due to light scattering in the various intermediate films used.

Frog Prince did make a Shadow masks with the set. Between 2-3 were made and were used as post masks to reduce contrast of the separation negatives, opening up the shadows slightly or even for color correction, by placing on the other color records. They are made by contact printing through and exposing through the blue filter, using the separation negative with a sheet of Kodak Pan Masking film, processed in HC-110 1:23 for 2.00 min (20 C). Sometimes these are called Contrast Reducing Masks (CRM), I think. If a high separation gamma is used such as 0.75-0.90 all three will be needed. Gamma of the separations could be controlled by controlling the percentage of time the mask was exposed with the separation negatives.

In the case of high contrast separation gamma, perhaps >=0.90 a highlight mask of the negative possibly called a “black mask” or “shadow highlight” can be made, and then contact printed with the separation negative to the pan masking film. This makes a contrast reducing mid tone mask with the effect of keeping shadow contrast high. I think the use of a “black mask” to make the main contrast mask was used more with Separation film since this operates better at 0.90 gamma and above, so the effect of shadow contrast gain will be higher.

Color correction on the transparency dyes itself can be performed using a set of isolation masks or chroma correction masks. They are made by first making a gamma 1 positive of all three separation negatives, using Kodak Commercial film 4127 or Gravure positive film. The separation positive is then contact printed with a different separation negative, onto a high contrast film such as Kodalith Ortho or Technical pan film. For Kodalith film, the mask is processed in D-11 straight for 2 min (20 C). Up to six of these masks can be made. They are exposed with the separation negatives for a fraction of the total matrix exposure time.

These isolator masks work by removing the unwanted absorption sidebands of the transparency, resulting in better color reproduction and saturation. Its used as a type of hold back mask when exposing the matrices, that isn't a 'negative' or a 'positive' image, rather it represents a pure color record that was blocked by the dye sideband absorption. Its also possible to use this technique in reverse, to de-isolate a given color, by printing the separation positive with different separation negative onto the matrix, if the transparency has an over correction for a certain color.

Area masks were made on litho film to keep a border on the image. Various litho film masks can be used as dodge or burn masks. Some masks were spotted by hand with crocein scarlet for dodging certain areas. From what people tell me, Frog Prince also dodged and burned matrices by hand, using adjustable wires on an XY axis jig to maintain color registration.

There is another type of important mask that was used infrequently, sometimes called a shadow contrast enhancement mask. This raises the contrast of the shoulder portion of the characteristic curve. Between 1-3 of these can be made. I think Frog Prince only made 1 of these if it was needed. There are two ways to make this type of mask. One is to over expose a piece of litho film with the transparency to get only the shoulder part of the curve, the other method (and probably more controllable) is to make the shadow enhancement mask off of the separation interpositives. Unfortunately I don't know how Frog made this mask. I think it may have been applied if there was an area on the transparency that was underexposed.

Here is an example of how these separations and masks might be exposed onto Kodak matrix film. Again I don't have their aim-points for exposing matrices, so I'm using some other information I have here.


Cyan Matrix:
exp.______________________________Time (s)
1 Separation + HL + CRM_____________12.5
2 Separation + HL + Red Isolator_______12.5
3 Separation + HL + Specular__________15.0
4 Separation + MID__________________10.0

Magenta Matrix
exp._______________________________Time (s)
1 Separation + HL + CRM______________15.0
2 Separation + HL + Green Isolator_______10.0
3 Separation + HL + Specular___________15.0
4 Separation + MID + Red Isolator_______10.0

Yellow Matrix
exp.___________________________________Time (s)
1 Separation + HL + CRM_________________ 0.0 – (1.3?)
2 Separation + HL + Blue Isolator___________25.0
3 Separation + HL + Specular______________15.0
4 Separation + MID______________________10.0
5 Green Sep. + Green HL + Blue positive_____10.0

 

[koraks]

Thanks for posting this, very interesting! Right off the bat, my first observation would be that it's little wonder this technique more or less disappeared with the advent of less time-consuming digital separation workflows.

 

[Lachlan Young]

This is also covered/ pretty thoroughly disclosed in Bob Pace's newsletters - along with quite a bit of contextual information about Frog Prince's practices/ material preferences that the OP seems to have not found. Yes, it's relatively advanced masking, but not anything that would have been totally alien to graphic arts workers of the era.

 

[IB Photochemistry]

This is also covered/ pretty thoroughly disclosed in Bob Pace's newsletters - along with quite a bit of contextual information about Frog Prince's practices/ material preferences that the OP seems to have not found. Yes, it's relatively advanced masking, but not anything that would have been totally alien to graphic arts workers of the era.

I would be interested to know what sources you know of that have this information. I have a copy of many issues of Keeping Pace (Bob Pace's newsletter) and have never found anything like this. I also have many books on graphic arts color separation techniques and none of that goes into much detail that would relate to DT.

Yes, Bob Pace has a different color isolation technique in his book, that isn't suited for the complete isolation of a transparency and is probably aimed at the amateur or individuals. I don't know if that technique was ever used in industry or at Frog Prince. Isolation masks can be more complex, than the example I gave from another source (not Frog Prince). I don't recall any discussion of long range highlight masks in Keeping Pace. If so, what issue does it appear in? His book does mention using HC-110 as a highlight mask developer, but there no mention that its used for a specific kind of highlight mask. As far as I know all of Bob Pace's publications don't mention multiple exposures using different masks on matrix film. And I have never found the END aim-points for Kodak DT dyes in any of his publications either.

I should probably add there are other kinds of masking and separation systems that were used as well in the DT industry beside the types I mentioned here. Some systems were very complex using six separations negatives and an array of special masks and filters. I think one of the masters of this was someone called Dick Rattan. Unfortunately I don't know much about him and what lab he ran, but he has been deceased since the 1980's. I have heard he could make DT's of Kodachrome's very well. There was someone else in the northeastern US named "Jack" (I don't have his full name) who also made exceptionally good DT prints.

Using Frog Prince as an example, I don't think they exploited all of the corrections using the systems I mentioned, probably due to time involved. There was a Cole Weston DT print in the produced in the mid 1980's by Frog Prince (I believe), and I recall it was a good print but not any better than most other other DT's I have seen from other labs. Most DT labs weren't making the best reproduction possible. When Kodak Separation Negative film was introduced in the DT industry it automatically masked some of the transparency dyes unwanted absorption's, and made reproductions easier.

 

[IB Photochemistry]

I think there are a few errors in the manual I posed here. This was likely a rough draft or an incomplete copy. As I needed to add a few other types of masks that weren’t included in the manual, based on those who worked at Frog Prince. I pointed out some of the omissions I could find, there are numerous spelling and grammatical errors as well. So far there haven't been any questions about this. I'm not sure I found all of the errors yet.

Another detail I recall about Frog Prince is that they might have used better isolation filters to the Wratten filters listed in the E-80 manual. Unfortunately, I don't know what filters they were using. In 1985 they might have still been using the E-80 recommended filters, as the manual lists them for a highlight mask exposure. The Wratten #47B and #61 have a lot of spectral leakage and are not aligned spectrally with most E-6 films (or even E-4 films). I have found by using a blue filter with a transmission peak at 445 nm, I could get at least a 10% increase in blue contrast with Super XX pan film. The filters used effect the masking equations, so any change in the spectral distribution may effect contrast and exposure.

In the Photograph Conservation Study Collection, at the The Metropolitan Museum of Art, there exists a complete set of masks and separation negatives, along with the matrices and dye transfer print, including the original transparency. The set is called the CVI Dye Transfer Set, (PCSC 2020), donated by Guy Stricherz in 2020. I have obtained permission to publish these images for academic research and non-commercial use. They contain images of the 3 highlight masks, 3 long range highlight masks, specular mask, 3 principle masks, separation negatives, 3 gamma 1 interpositives, 6 color isolator masks, 3 shadow masks, and an area mask. However since they are recent, from 2020, and I'm also not sure if Photrio.com would qualify for educational or non-commercial use. If its not a good idea for me to post these images here I can send them to anyone interested by contacting me privately.

I do have a procedure for making separation negatives using Kodak Separation Negative type I film that differs slightly from the procedure using Super XX pan. There is a procedure using Kodak Negative Separation film, from Bob DeSantis a former DT lab operator (who died in 2019), that has been distributed to some people. I don't know how complete the procedure is, as it is missing some information. I'm not really sure this came from DeSantis himself or someone affiliated with his former lab.

The main issue with Kodak Separation Negative films is that they develop very quickly and are prone to uneven development. Kodak Separation film is developer incorporated and designed for roller transport processors. Some people who used this film outside a professional lab without a roller transport processor, used a rolling technique in a tray of developer. I haven't done a lot of tests with Kodak Separation Negative film tray development since I have a roller transport processor. I would suspect using a surfactant such as Sodium Dioctylsulfosuccinate (Aerosol OT), or Teepol M, or Igepol (or other anionic surfactants), might slow down the rate of development slightly to allow for better uniformity in addition to a pre-wet. Other than development issues it is sharper than Tmax and other pictorial films, with much better characteristics suitable for the application. If you have developed Kodak Separation Negative film using tray development, please share your method here. I would be interested to know how you can get below ± 0.01 total density uniformity error for the entire film surface with tray development easily or if they can be processed in rotary tubes such as a Jobo Expert drum. I have used nitrogen burst development and got good results with that.

Most people here haven't made DT prints professionally, but those who have, haven't commented. Remember, Kodak had an absolute monopoly on DT and trained customers and their affiliates at a special lab which I believe to be located at the Eastman Kodak Marketing Education Center, using some of these techniques (not published anywhere). These methods were common knowledge among DT professionals.

There have been several attempts to manufacture “dye transfer” materials in the last 30 years or so. Of those few attempts no one has published a good system of making separation negatives. Its hard to try to market something that most people can't use very well, because they don't have the proper knowledge to control it. In the late 1990's Dr. Jay Patterson (now deceased), a psychiatrist, manufactured and sold a complete system for making dye imbibition transfer prints, except separation and masking films, under the name of Dye Transfer Corporation or DTC. As far as I know publications from his company or from anyone else, who manufactured “dye transfer” type materials never provided a good system for making separation negatives from color transparencies. All the information published was highly inadequate for making good separations.

One may argue that the best method in “this day and age” is to make digital separations. That's great but how does one go about doing this? Its much more complicated than it appears. I have a briefly looked into this technique, but I am by no means an expert in digital imaging. I have found a few areas which are problematic or are cause for concern. This does tie into making conventional separations. Perhaps if this needs further discussion a thread in the hybrid forums would be better.

Drum scanners, area array scanners, and linear array scanners all provide different results, when scanning film. Drum scanners (probably the most preferable type for making separation negatives) differ widely in performance and characteristics, as well as the competency of the operator. That is not to mention the software issues. These were designed primarily for the graphic arts industry, and usually not for high resolution scanning of film. Most do not correct the dye spectral sidebands of a color transparency, doing this usually requires work with the digital file. Someone competent in this might not have an issue with it. I don't think most scanners of either 3 types provide color isolation of the transparency dyes, but I am only familiar with a few kinds of scanners.

The 'S' curve for a transparency aids with viewing the transparency but creates problems when printing because of the product of the matrix film curve and the transparency curve, results in loss of detail in the highlights and shadow tones. One will need digitally linearize the transparency characteristic curve or make separate highlight masks to correct this problem. Again I'm not entirely sure how one would do this well without losing image data.

Digital film recorders differ in resolution, bit depth, and image quality. There are numerous issues with software drivers and, most run on older operating systems. I think most film recorders are 8 bit per channel, or 256 tonal levels per channel. For a type C print, or black and white silver print, that might be fine, but in order make a good matrix with its tonal range above 3.00 D, an 8 bit image could cause a loss of image data. The challenge is to either make a separation negative with perhaps 16 bit per channel, or make a separate negative for highlight information along with the main color record. I'm not exactly sure what the best way to do this is.

I have heard those doing this for making DT separation negatives are using special custom software, which is not available to anyone. Yes, I'm aware James Browning had a simple color separation program and source code, one could download, but all that did was separate the image into three color records and apply a linear color correction mask for the printing dyes. It did not the correct the curve of the transparency, correct the transparency dye spectral sidebands, or address the 8 bit per channel bottleneck. I know of no references which will provide a complete procedure for doing this well. These are a just few of the main problems I can find.

It may be possible to use Ilford FP4, HP5, Foma pan, or Tmax to make separations and masks, but it probably wont work as well as the old films. There are a few people who claimed to have make good separation negatives with pictorial films, but there is no published documentation of how this was done. The optimal curve shapes may not match and may not be at the same gamma. I have never tested these pictorial films, so I don't know how well they work. All the curves of Tmax 100 (in HC-110, Tmax RS, etc. ) I have seen don't look that great to me. As grainy as Super XX pan is, it produces a nice long flat curve with an MQ developer.

As far as I know there isn't a panchromatic lithographic film currently manufactured, that can be used to make highlight masks. If there is something like this still manufactured please respond on this thread. There might be a red sensitive laser image setter film that might work to make red light highlight masks. Films like Ilford Ortho could be used to make (blue and white) highlight masks, gamma 1 positives, and color isolator masks. However, tricolor highlight masks could be made off of the gamma 1 interpositives, using high contrast ortho film. This method is not the most controllable or preferable, since they should be as sharp as possible.

Most pictorial films do not process well to a low gamma, like Kodak Pan Masking film is designed to do. I have heard of others using the Ilford pictorial films for masking, with diffusion material. High silver content “super XX” type films might also work better.

 

[koraks]

if Photrio.com would qualify for educational or non-commercial use.

Yes, it would. If you're unsure, you could always publish through something like archive.org or Wikimedia Commons. But it all boils down to pretty much the same: the information would be freely accessible to anyone, at no cost.

 

[DREW WILEY]

Frog Prince was just one lab among many, and a rather small one at that. There were different methods. And of course, all the films in question are no longer made. And exposure data points aren't of much value unless someone else has exactly the same outdated equipment.

You are completely wrong about old versus new films. Better separations as well as contrast masks can be made any day of the week using a modern film like TMX100. No need for Super-XX or Pan Masking Film. The question nowadays is more about the very high cost of sheet film of all types.

All DT workers had a hard time with specular highlights. One strategy was to just go ahead and overprint the highlights with some kind of inevitable color tinge, then selectively bleach that away afterwards.

Jim Browning is an electrical engineer who holds patents on the Chromira printer system. He designed his own registered 8x10 film recorder, and it's apparently unique. Jim isn't hoarding anything. He'd be willing to make separations for others; but the whole problem is that these need to be tailored very specifically to the end user, who would naturally do certain things differently than he does, and would have a different registration setup anyway. He can hypothetically also output digital camera files onto sheet film. Up till recently he used 8X10 TMX100, but due to its increasing cost, switched over to Delta 100 once he figured out how to tweak its files.

Using D100 traditional darkroom style would be a lot more challenging; FP4 would be a much better alternative. Andy Cross has been using FP4 for separations for a long time. HP5 would be relatively worthless for that application. Fomapan pseudo-200 would be nightmare; it does have a long straight line, but poor batch to batch quality control, and can't be developed to a high gamma. But I did test it once just out of curiosity.

I have no interest in writing a separation manual. The practical demand is zero. One needs to orient their separations to their specific output media, anyway; and a lot of people like gum printers just aren't that picky.

The last pan film used for highlight masks was Tech Pan. There was a Euro substitute for that which was liquidated about 20 yrs ago, but had questionable quality control, perhaps from being out of date. There are workarounds for that issue too. For highlight sparkle in just certain areas, all it takes is a fine point Sharpie pen on a registered sheet of frosted mylar; I've done that many times for Cibachromes. Image setter film is down to residuals; very few people still use it.

But yeah, I've seen 16 sheet DT results that weren't any better than just 3 sheet separation results. Just depends on the methodology. Everyone seems to have had their own tricks. The process would be horribly expensive to revive at this point.

The ideal would be to completely re-invent the matrix film itself for sake of a longer straight line. That would solve a lot of problems, but isn't going to happen either.

 

[IB Photochemistry]

Frog Prince was just one lab among many, and a rather small one at that. There were different methods. And of course, all the films in question are no longer made. And exposure data points aren't of much value unless someone else has exactly the same outdated equipment.

You are completely wrong about old versus new films. Better separations as well as contrast masks can be made any day of the week using a modern film like TMX100. No need for Super-XX or Pan Masking Film. The question nowadays is more about the very high cost of sheet film of all types.

No I'm not “completely wrong” about Tmax100. If you have researched this more than I have please post your curves traces here or your real evidence. I can do the same with Super XX pan traces that I made myself. Further I have the empirical evidence of this from a lot of research I have done. Given Tmax 100 was never designed to make separation negatives, but Kodak listed it as a possible substitute for Super XX Pan and Separation Negative Types I and II following discontinuance in the mid 1990's; IN NO WAY WAS IT BETTER. Kodak Separation Negative film is superior to Super XX pan and Tmax100 for making color separations from a technical point of view. No professional labs used Tmax 100. If its so much “better” than “old films” then please post your curves along with a detailed procedure that others can reproduce. This is your opinion not a statement of fact. My opinion is that these “old films” perform better. I know I need to be careful here and respect your opinion and follow the forum rules.

 

[IB Photochemistry]

Jim Browning is an electrical engineer who holds patents on the Chromira printer system. He designed his own registered 8x10 film recorder, and it's apparently unique. Jim isn't hoarding anything. He'd be willing to make separations for others; but the whole problem is that these need to be tailored very specifically to the end user, who would naturally do certain things differently than he does, and would have a different registration setup anyway. He can hypothetically also output digital camera files onto sheet film. Up till recently he used 8X10 TMX100, but due to its increasing cost, switched over to Delta 100 once he figured out how to tweak its files.

Using D100 traditional darkroom style would be a lot more challenging; FP4 would be a much better alternative. Andy Cross has been using FP4 for separations for a long time. HP5 would be relatively worthless for that application. Fomapan pseudo-200 would be nightmare; it does have a long straight line, but poor batch to batch quality control, and can't be developed to a high gamma. But I did test it once just out of curiosity.

James Browning is listed as a co-invented in some of the Chromira patents. My understanding is he did not engineer the Chromira printer; I think his job for Chromira was the development of software to run the machine. He designed his own film recorder and system for making separation negatives. And its my understanding he doesn't have an engineering degree, but is really interested in computer science and digital technology. I don't have anything positive to say about him or his projects relating to DT. My advice to others is to do their own research in regard to making separations or “DT”, and not rely of him to be the arbiter on all matters related to DT. Again I have to be very careful on this platform, as I'm not going to attack him on here because it might be construed by some as a slander.

That's great Andy Cross found a way to do this using conventional camera films. Unfortunately, he hasn't published his complete system so it can be reproduced, as far as I know. If I'm wrong about this please let us know where he published his complete system.

 

[IB Photochemistry]

The last pan film used for highlight masks was Tech Pan. There was a Euro substitute for that which was liquidated about 20 yrs ago, but had questionable quality control, perhaps from being out of date. There are workarounds for that issue too. For highlight sparkle in just certain areas, all it takes is a fine point Sharpie pen on a registered sheet of frosted mylar; I've done that many times for Cibachromes. Image setter film is down to residuals; very few people still use it.

But yeah, I've seen 16 sheet DT results that weren't any better than just 3 sheet separation results. Just depends on the methodology. Everyone seems to have had their own tricks. The process would be horribly expensive to revive at this point.

The ideal would be to completely re-invent the matrix film itself for sake of a longer straight line. That would solve a lot of problems, but isn't going to happen either.

No, Kodak Technical Pan was never used for making highlight masks commercially. There were references to tech. pan being used for highlight masks in publications for amateurs, probably because it was easier to work with. Kodak Contrast Process pan was another film used for making highlight masks.

Besides the long range, short range, and specular highlight masks, there were a few other types. I'm aware of something called a “super specular” mask. I don't know how it was made. Tartaro Color lab apparently made these a lot.

Dye Transfer was always “horribly expensive”. Since your background was in retail sales (I think), from a purely commercial point of view it may appear very remote to revive it. However I have to strongly disagree with you; it can certainly be done to make a dye imbibition transfer print system, without the need of large commercial volumes. If Egbert Haneke can get nearly 2 million euro [a rough estimate of mine] to coat several kilometers of film and paper (a few years ago), that is a very small investment in terms of the overall imaging market. He could change his mind and allow some of that to be sold. I'm not going to convince Drew here of anything; he will write what he believes all the time. I am just trying to give another opinion.

One doesn't need to “completely re-invent the matrix film itself” to improve the highlight rendition problem. It's also a function of matrix processing, the dye used, the transfer chemistry, and the mordant. This is not exclusively a problem with the matrix material. Kodak Matrix film 4150 is probably better than any other film made for this application of hand rolled transfers.

 

[DREW WILEY]

IB - I'm not going to waste time arguing with you over Tech Pan, TMax, and so forth. You are entirely incorrect, and are basing many of your opinions on highly outdated information.

The Hanekes didn't just get a materials grant, but indeed had to redesign their matrix film and receiver paper for their own specific blue laser workflow, which is a dead end to anyone else, because all that equipment itself is now obsolete and can only be maintained by cannibalizing the spares they acquired for exactly that purpose.

And let's just look at the cost of sheet film itself. It has almost quadrupled in recent years. I'm not trying to discourage anyone. More power to you if you think you can pull it off.

My sales background was construction related. Sales of 40K to 75K or higher were common. That included Govt agencies, defense contractors, building contractors, pharmaceutical plants, industrial facilities including refineries, shipyards, and yes, big photo labs too. Some of the clients were the richest people on earth. So yeah, if one of those folks were interested in a philanthropic venture reviving a classic form of printing, it would be just pocket change for them. They could probably even set up a dye transfer station inside their billion dollar yacht, or on their private Island. But for the rest of us it would be a little more problematic to fund.

 

[Lachlan Young]

and none of that goes into much detail that would relate to DT

I don't think you have much contextual understanding of colour separation within the wider graphic arts (which dye transfer drew from rather than vice versa - the practitioners weren't some sort of quasi-superhumans, but they did have the nous to borrow knowledge and techniques from other colour separation workers who were working in adjacent trades - they weren't in silos - as much as some managers might have liked them to be). Most of the various masks and other tone separation techniques are not alien (in fact they were routine) to specialists in things like screen print/ serigraphy. None of this is particularly unique or innovative (or someone would have patented it) - and quite frankly whatever 'secrecy' there may have been will have been more because it was in many cases very arcane - and/ or straightforward enough (to those skilled in the arts) that it would have saved a competitor hours of trial and error.

Fundamentally you seem to want to confuse skilled & experienced work performed by competent workers with some sort of jealously guarded secret/ mystical knowledge - the materials were, at best, largely early 1950s technology, and the reason why people have been able to make Dye Transfer materials successfully at a craft level, is because the process is fundamentally that - a craft process, helped along by a few high precision tools. It is not really different from other colour assembly processes, it's just that it uses gel matrices and dyes derived from the fabric dye world, rather than plates or screens and inks.

I'm also still waiting for you to post clear sensitometric evidence that Separation Neg Film Type 1 had masking effects. Just remember that DT wasn't the only industry that used it (in fact all evidence suggests that it borrowed it) - and Kodak would have made it very clear in the data supplied to those other industries if it did.

 

[DREW WILEY]

And Kodak certainly wasn't the only maker of matrix film etc. Some of the primary teachers like Bob Pace had backgrounds in offset printing plus sometimes carbro printing too. And he mainly taught lab pros (not "amateurs", whatever that does or doesn't actually mean in this context).

Reviving DT printing matrix film would just be the tip of the iceberg, and perhaps the easiest part except for dyes themselves. You'd almost have to revive entire industries, especially if you're going to outright reject proven usage of currently available films with respect to masking and separations. Even fixing out and mordanting your own FB receiver paper now involves far more expense than just a couple years ago. You'd also have to come up with a fresh round of registration gear for those potentially interested.

Then in terms of marketing, that involves a lot of developed inter-personal connections, proving trustworthiness.
And workshops would probably be needed too. That too needs inter-personal skills. And where are younger people who can hardly afford rent today going to find all that darkroom space? You can argue that new commercial printers could get around that financially. But why would they gamble on something with a very limited clientele base, and with far higher costs than in former days? Who is going to invest in it if they expect a financial return? And just how many current DT printers are still going to be active or even alive a decade from now? Certainly not many, if any at all.

The bigger DT labs were assembly-line setups anyway, involving a range of personnel, with each one specializing in a single step of it. For small shop users that could be simplified by drum processing with a different kind of development of the matrices, more akin to the former Eastman wash-off relief method. I've tested it; and even certain big labs went that route in terms of a slower-acting, more cost-effective, and more controllable developers.
The workflow just wasn't as fast. All kinds of things are hypothetically possible.

But in a world where everyone is in a hurry, and where inkjet printing is now as ubiquitous as shoes, the niche for DT is going to be very very small. Other interests have also looked at it, which were in fact themselves well funded in advance, but then stepped away from the brink once they realized that there was no longer a realistic market for it.

Otherwise, all that talk about midrange masks or progressive highlight masks and so forth would be easy-peasy for me with ordinary TMax. But I'm very skeptical they were ever used much in DT workflow. I do know of an exception; but I wouldn't call his own DT prints all that remarkable. Hopelessly grainy in fact, with all that grain build up one sheet after another of Super-XX in combination with small originals.

Those allegedly "perfect" sep films of yesteryear (Super XX and Color Sep) also had serious difficulty with the blue separation gamma, which had to be significantly offset in the matrix film development itself. You don't get that issue at all with TMX if you know its sweet spot. That was factored into the engineering of TMX 100 from the get go by Kodak, as a deliberate improvement over the former alternatives. They knew what they were doing.

 

[IB Photochemistry]

IB - I'm not going to waste time arguing with you over Tech Pan, TMax, and so forth. You are entirely incorrect, and are basing many of your opinions on highly outdated information.

With all due respect I need to disagree with you. To be perfectly honest I don't think you can cite any source where Tmax was used commercially. Since Tom Rankin has been deceased for a long time, I can say that in the mid 1980's he did like to tell others who asked about this that they were using TMax 100, in order to protect trade secrets. Some time in the early 1990's they got a Versamat processor and used Separation Negative films.

There were two uses for Tech. pan in the DT field that I can verify. One was for color isolation masks as there can be many variations of that technique. The other was for use as a red separation film for color negatives. The cyan indoaniline dye created by oxidized CD-4 developer has an absorption peak around approximately 690-710 nm. Whether Tmax, Super XX pan, or Sep. Neg. film was used, they don't have good sensitivity above 650 nm. Sometimes this would be a problem so Tech. Pan was sometimes used since it has sensitivity in the deep red region.

 

[DREW WILEY]

I wish you well on your endeavor. But like I already stated, I have better things to do with my time rather than trying to convince someone who hasn't done their own homework yet. And there are ZERO "trade secrets" going on about sep film usage.

Like Lachlan tried to explain, a lot of this is simply about craft. If someone got really comfortable working with Super-XX, for example, they probably wouldn't switch to another film unless they had no choice. Recalibrating separation protocols to a new film can be a LOT of work.

And once TMax film started taking off, the right hand of Kodak wasn't communicating well with the left hand, so to speak, in this respect. A new high performance separation film was becoming available in fashion of TMax, but the left hand of Kodak was getting downright flakey in terms of ongoing commitment to DT itself, and certain batches of yellow dye and transfer paper were slipping in quality control. That's why practitioners woke up to the fact that they better stockpile as many familiar DT supplies as they could before it all came crashing down.

Both Super-XX and Matrix film involved such old coating machinery that they were doomed anyway.

I'm well aware of the extended red sensitivity of Tech Pan. I used it in conjunction with heat lamps for detecting underpainting on canvases. But using Tech Pan for red separations per se? That wouldn't make much sense. Yeah, I know how to do that too; but it's not practical at all in terms of general workflow. I do know of a paper postulating the hypothetical use of Tech Pan in such a role; but an actual experiment never was performed, even by its author.

Citing sources for TMX sep usage??? Haven't I given enough clues already? I got all kinds of responses both from Google and actual practitioners. You just have to ask in the right manner, and not insinuate they're trying to hide something. They're not. Up until quite recently, by far the largest consumers of 8x10 TMX 100 were industrial users, not shooters. I got my own stockpile of 8x10 boxes at reasonable pricing as the leftovers from those big commercial use orders, which included serious color sep applications.

 

[IB Photochemistry]

I don't think you have much contextual understanding of colour separation within the wider graphic arts (which dye transfer drew from rather than vice versa - the practitioners weren't some sort of quasi-superhumans, but they did have the nous to borrow knowledge and techniques from other colour separation workers who were working in adjacent trades - they weren't in silos - as much as some managers might have liked them to be). Most of the various masks and other tone separation techniques are not alien (in fact they were routine) to specialists in things like screen print/ serigraphy. None of this is particularly unique or innovative (or someone would have patented it) - and quite frankly whatever 'secrecy' there may have been will have been more because it was in many cases very arcane - and/ or straightforward enough (to those skilled in the arts) that it would have saved a competitor hours of trial and error.

Fundamentally you seem to want to confuse skilled & experienced work performed by competent workers with some sort of jealously guarded secret/ mystical knowledge - the materials were, at best, largely early 1950s technology, and the reason why people have been able to make Dye Transfer materials successfully at a craft level, is because the process is fundamentally that - a craft process, helped along by a few high precision tools. It is not really different from other colour assembly processes, it's just that it uses gel matrices and dyes derived from the fabric dye world, rather than plates or screens and inks.

I'm also still waiting for you to post clear sensitometric evidence that Separation Neg Film Type 1 had masking effects. Just remember that DT wasn't the only industry that used it (in fact all evidence suggests that it borrowed it) - and Kodak would have made it very clear in the data supplied to those other industries if it did.

There is a difference between graphic arts color separations and continuous tone tricolor separations. I'm not saying there aren’t similarities there certainly are. The methods used to make DT separations were a guarded trade secret, and only known to others in the DT field with Kodak affiliation.

There are a several goals of making good separation negatives for DT. First, the tone curve must be linear in additivity and proportionality. Second, the modulation transfer function needs to be maintained, so as to minimize losses due to copying. Third, masking is used to maintain Equivalent Neutral Density of the new dye system. Fourth, maintaining the proper density range of the new dye system, again this was used frequently in graphic arts. Fifth, due to non-linear effects of the transparency-matrix-dye-mordant system, curve modification is needed to preserve highlight detail. Sixth, restoring color saturation to the print image due to dye sideband absorption.

Yes, I can post my curves of Sep. Neg. Type 1 here that demonstrate an internal masking effect. I am aware that DT wasn't the only industry using it.