Kodak Ektacolor Laboratory Film - researched by Michael Talbert

Index to this web page:
Michael Talbert
has provided a considerable amount of historical information on the early Kodak print films, Kodacolor, Ektacolor and Vericolor, plus their printing processes. This is set out below.
To assist in reaching a specific topic, please use the hyperlinks in the following index. The images and the Intellectual Property Rights pertaining to the text article, belong to Michael Talbert.
Also, see his research on Kodacolor and Ektacolor Camera Film.
Also, see his research on Ektachrome transparency slide film and prints on Ektachrome RC paper.
Also, see his research on early Agfa colour print materials.
Also, see his research on early Gevaert colour print materials.
Also, see his research on Ansco colour print materials.

For an insight into what is happening with Kodak since its demise, here is a link to a New York Times Business Day article, by Quentin Hardy dated March 20th, 2015.
Entitled "At Kodak, Clinging to a Future Beyond Film". it makes interesting reading, complete with a 5min and 33secs video.
"What happens when a tech company is left for dead but the people left behind refuse to give up? At Kodak, the answer is to mine its patents for gold".

Internegative Films, Print Films and Slide Films
  1. Colour Internegative Films
    History; Earliest 'Colour Internegative' films for still photography
    Agfacolor ZN Film
  2. Ektacolor Internegative Film
    Balancing the exposure and 'shadow to highlight' balance for batches of Internegative film
    Kodak Internegative Film Type 6008
    Kodak Internegative Film Type 6110
    Processing Kodak Ektacolor Internegative Film
    Internegative Replenisher Solution

    Kodak Vericolor Internegative Film 6011 and 4112
    Vericolor Internegative Film 4114, Type 2
    Processing Vericolor Internegative Films
    Kodak Commercial Internegative Films

  3. Kodak Ektacolor Print Film
    Chronology of Ektacolor Print Film
    Exposure and Processing of Early Print Film - 6105 thr' 6108

    Ektacolor Print Film ~ Later Type - 6109

    Ektacolor Print Film - 4109
    Kodak Vericolor Print Film - 4111

  4. Kodak Ektacolor Slide Film
    Introduction ~ Type 5381 and (Later) Type 5028
    Kodak Vericolor Slide Film 5072


  1. Processing Ektacolor Print and Slide Films (after 1955)
    Ektacolor Print Film Additive (from 1964)
    Ektacolor Print Film Stabilizer

    Processing Ektacolor Print Film 6109 and 4109 in the Kodak 30A Rapid Processor


  1. Acknowledgements

Many illustrative images, provided by Michael Talbert, are embedded within the following text.

Charlie Kamerman has (February 2012) sent me some pictures of items within his amazing collection of early Kodak films. Charlie says "I have hundreds of boxes of film from 1891 through the 1980's."
To view just a few, please click here.
And do take a look at Charlie's site www.Kodakcollector.com

Internegative Film, Print Film and Slide Film

The content of this page should not be confused with the camera films (negative for prints and slide film for transparencies) as used in amateur and professional cameras (roll film, 35mm film and sheet film).
The materials described here were used in photographic laboratories for the specialist purposes identified in the Note below.

Internegative Films
were used for making negatives from transparencies without the need for contrast masking, the negatives then being printed onto Ektacolor paper.
Print Film was designed for making large display (positive) transparencies from colour negatives and Internegatives.
Slide Film was designed for making 35mm and 46mm transparencies from colour negatives and internegatives

Colour Internegative Films

Colour Internegative films were designed for producing colour negatives directly from colour transparencies. The resulting negatives were then used for making colour prints or enlargements on a colour negative printing paper, or colour transparencies could be obtained by printing onto a colour print film, such as Vericolor Print Film.

Although more direct methods of making colour prints directly from colour transparencies have been used since 1941, a colour internegative generally gave a far better reproduction of a transparency compared to a print made using colour reversal paper (see Kotavachrome prints and Kodak Colour Print Material, Type R)

In the 1930s to 1950s colour prints were also being made from colour transparencies by the Tri-Chrome Carbro and Dye Transfer processes (not described here).

History; Earliest 'Colour Internegative' films for still photography
Although not a colour internegative film as such, in the early 1940s Motion Picture colour film was being used at the U.F.A. studios at Babelsberg, Germany by Agfa to make duplicate negatives for motion picture films. As best is known, the film was a soft gradation colour reversal film, printed from the original colour negative as shot in the camera. This film would produce another colour negative which was used to make colour positive prints. The duplicate negatives were never used to make full length films, but only for “lap dissolves” and special effects which were then spliced in with the original negative.

Eastman Kodak introduced “Eastmancolor Internegative Film Type 5243” in 1951 for use in the Motion Picture industry. It is possible that internegatives were made on this film from release prints made on “Eastmancolor Print Film, Type 5381” .

In the USA, Eastman Kodak began a service in 1949 for making colour prints from amateurs’ colour transparencies. The transparencies, mainly 35mm, were printed onto Kodacolor (camera type) film, possibly Type A, and then prints were made from the internegatives on Kodacolor paper.

Agfacolor ZN film
It is possible that the first type of internegative film specifically designed for making negatives directly from colour transparencies was “Agfacolor ZN film”. Agfacolor ZN film was an unmasked colour negative film, presumably balanced for tungsten illumination, which could be used to make contact or enlarged negatives from Agfacolor transparencies. Although the transparencies could be printed onto the film directly, Agfa recommended for best results a black and white contrast reducing mask should be made from the transparency first to be used in register with the transparency when printing onto the ZN film.

As far as is known, the film was introduced in 1956, and the development time in Agfacolor negative film developer S was 6 to 7 minutes. It is believed to have been taken off the market by the early 1970s.

On a personal note, Michael Talbert met someone who, allegedly, knew something about this film. Forty one years ago, while working as a colour printer in London and during a discussion with other printers, Agfacolor ZN film was mentioned. One of the printers was a German lady who ventured to say she had used, or at least known, something about the film. When asked if it was any good, she replied “Rubbish !”.

Ektacolor Internegative Film
Before Ektacolor Internegative Film was marketed, internegatives from colour transparencies were being produced on Kodak Ektacolor Camera Films Type B and Type L. In the first edition of “Printing Color Negatives” by Eastman Kodak, published in 1958, there is a section on “Printing Color Transparencies”.

The recommended procedure was to make a contrast reducing mask from the transparency onto Kodak Pan Masking film. This was registered and attached to the transparency when enlarging and exposing the transparency onto Ektacolor Type B or Type L film. The mask then reduced the contrast to the level that could be accommodated on the Ektacolor films.

Printing the transparency directly onto Ektacolor film did not work as the internegative would be far too contrasty and the print would exhibit burnt out highlights and dense shadows with no detail in them. The author has tried this method of making internegatives on Ektacolor Professional Type L film and came to the conclusion that only an extremely soft contrast transparency would give an acceptable result.

Prints made from internegatives made on Ektacolor Type B and L films, in which the colour laboratory had taken the trouble to make the internegative from a masked transparency, gave good results, but the masking was a separate and time consuming procedure and added to the cost of the internegative.

In 1961, Eastman Kodak introduced “Ektacolor Internegative Film” in sheets, and “Internegative Color Film” in 35mm rolls. Transparencies could be printed onto these film without the need for masking.

Ektacolor Internegative Film is mentioned in the Kodak Data book, “Color Films”, 4th edition, published in December 1961. The book mentions that “Information on producing internegatives on this film could be obtained by request from the Sales Division at Eastman Kodak, Rochester 4 N.Y.”

In the UK, in the “Kodak Professional Catalogue” for 1963 the 35mm version of internegative film is listed for sale in lengths of 80 feet. Ektacolor Internegative film in sheets was introduced into the UK in 1963. The film is first mentioned in “Kodak Professional News” for March 1963 with almost a page of description and warns that the film requires a “special developer and starting solution” and that the film and developer chemicals are not classified as a “stock line”, which means they had to be specially ordered. Not listed in the UK Kodak Professional Catalogue for July 1963, the Kodak “Trade Circular” for September 1963 lists the film in three sizes as a “new” product, and Ektacolor Internegative sheet film was later included in the Kodak Professional Catalogue for July 1964. In this UK catalogue for 1964-65, three sizes were offered for sale – 4 x 5 inches, 5 x 7 inches and 8 x 10 inches.

Ektacolor Internegative film in sheet film format was designed to make internegatives at exposure times of 1 to 16 seconds with a 3200°K light source.

Most internegatives were made through an enlarger with a colour head, enlarging 2¼ inch square transparencies onto 4 x 5 inch sheet film to make an internegative about 3¾ inches square from the whole of the transparency. 35mm transparencies were enlarged to about 4¾ x 3 inches and negatives from 5 x 4 inch transparencies were made to 3½ x 4½ inches. The larger the print ordered from the transparency the larger the internegative. 10 x 8 inch negatives were not uncommon when making mural sized prints.

Below are shown two boxes of Ektacolor Internegative film dated over 10 years apart. The method of exposing the film hardly changed during the life of the film, 1961 to 1979, apart from the minimum exposure time being decreased from 1 second to 1/10 second in the mid-1970s. Also by the mid-1970s, the catalogue No. was being printed onto the labels. “May 1979” (RHS box) is the advised “Develop Before” date. It is possible that this box of film was from one of the last batches of Ektacolor Internegative film manufactured.



Below: Rear label of the above “Feb 1969” box, with a good description of the film

Below: Rear label of the above “May 1979” box with the storage instructions in seven languages.
This type of label, in varying forms, was introduced for colour sheet films in 1969.



Balancing the exposure and 'shadow to highlight' balance for batches of Internegative film
The instruction sheet enclosed in each box of internegative film gave a starting filtration of 50 Yellow, 20 Magenta, (50 20 --), to be made up of Kodak filters or dialed into an enlarger colour head. Trial internegatives were made from a transparency which was reasonably well colour balanced and showed no colour cast.

The suggested starting exposure was 10 seconds and, with the filtration of 50 20 --, three or four trial internegatives were exposed at different apertures, keeping the exposure at 10 seconds. When processed and dried, one of these tests would have been correctly exposed, or very nearly so.

A correctly exposed internegative tends to look slightly “thinner” than a correctly exposed camera film negative, such as a negative made on Vericolor or Ektacolor films.

The best possible print was then made from the chosen test internegative, concentrating on filtering the mid tones to the correct balance

If the mid tones had been filtered as near as possible to a fairly neutral balance, it is likely that the high lights would show a colour cast, and the blacks and shadow areas would show the opposite cast.

For example, if the colour cast in the high lights was Magenta, the shadow areas tended to look green. This meant that the contrast of the green sensitive layer was too low.

In this case, it was possible to correct the balance of the print by adding a filter of the same colour cast as the overall shadow area cast or, better still, decreasing the filtration of the opposite colour, magenta.

The starting filtration was 50 Yellow, 20 Magenta, so another test internegative was exposed at, say, 50 Yellow, 10 Magenta, and another test at 50 Yellow, 5 Magenta, keeping the exposure time slightly less this time, on account of the change in filtration, i.e. say to 9 seconds and 8 seconds, respectively.

The contrast of the internegatives could also be corrected at this point. If the test print was too low in contrast, a slight increase in exposure would increase contrast. If too high in contrast, a slight decrease in exposure would lower the contrast. Suppose in this case the contrast was judged to be too low. The test internegatives could be exposed at 14 seconds and 12 seconds, respectively.

One of the prints made from the second test internegatives would have shown an improved colour balance in the print. The internegative exposure giving the best print could be used for making internegatives from the vast majority of transparencies. The exposure of the internegative film could be increased or decreased according to the contrast of the transparency. With experience, the shadow to highlight balance of badly exposed transparencies with colour casts could be modified by filtration and exposure changes to give a much improved copy.

Very under-exposed transparencies were given one stop more exposure by altering the aperture of the enlarger lens and, correspondingly, very over-exposed transparencies were given one stop less exposure. Similar to duplicating, under exposed transparencies always printed more successfully.

During the early 1970s, the exposure range was changed to 1/10 second to 16 seconds.

Described above is a method of finding the correct filtration and exposure for any batch of internegative film by trial and error. The Kodak instruction leaflet enclosed in every box of film gave an alternative procedure. This involved taking densitometric readings from grey scales exposed onto internegative film with a densitometer and plotting three separate D log E curves* of the red, green and blue densities of each film layer.

(*D log E = density of the actual dye in the film plotted against the logarithm of the exposure)

Both methods work, but the one described in the text, above, is possibly easier to carry out, achieves the same result in the end, and doesn't require any knowledge of photographic densitometers (and equipment) or of plotting graphs.


Kodak Internegative Film Type 6008
Kodak Internegative 35mm film and other roll sizes in the USA

An internegative film for making colour negatives directly from colour transparencies without the trouble of making contrast masks was introduced in the USA in 1961. The film was most likely to have been a modified version of a type of internegative film used in the motion picture industry, such as Eastmancolor Intermediate film, 5253.

By 1963 Internegative Color Film was available in 80 foot rolls of 35mm size, 100 foot rolls in 46mm size, and 100 foot rolls at 2.423 inches width.

It is thought that the films were processed in the special Internegative Replenisher with the addition of Starting Solution from the introduction of the film. The remainder of the process consisted of the normal C-22 chemicals, as used to process Kodacolor and Ektacolor films. The modified process was known as “Process N-31”.

In 1970 the film title gained the numbers 6008, and was still being sold in 1977 in the same sizes, plus a 70mm wide roll size of 400 foot length. Vericolor Internegative film, 6011, initially known as SO-406, for processing in the C-41 process, replaced Internegative Color film 6008 in 1978, and the new Internegative 6011 film was processed in the same developer as used for all process C-41 films.

Kodak Internegative 35mm film in the UK
Kodak Inter Negative Colour Film was introduced in the UK in August 1961 in 35mm size in 80 foot rolls. Notice that the word Internegative in the UK was wriiten as two words i.e Inter Negative. It appears thus in the Kodak UK Trade Circular for 1961, and in the Kodak UK Catalogue for 1962. By 1963, Internegative became one word in the UK. It was always one word in the USA; the earliest reference found being to Ektacolor Internegative sheet film, dating from July 1961.

It was recommended at the time to process the film in C-22 chemicals with a reduction in the normal development time as given for Kodacolor and Ektacolor films.

The film was included in the 1962 and 1963 Kodak UK Professional catalogues. There was a printing mistake in both catalogues; purchasers of the film were advised that there was “……………………a modification in first development time.” There was only ever one developer in the C-22 process, and the mistake seems to give the impression that C-22 was a reversal process with a first developer and a colour developer! The mistake was corrected in the Professional catalogue for July 1964. By this time Ektacolor Internegative sheet film was being offered for sale in the 1964 catalogue, having been introduced as a “special order” item in March 1963. Both the 35mm rolls and the sheet film were imported from the USA.

It was recommended to process the sheet film in a developer made up from Internegative Replenisher and Internegative Starting solution, and both these chemicals were listed for the first time at the end of the “Colour Materials” section in the July 1964 catalogue. Both the Replenisher and the Starting solution were being imported from the USA.

By 1969, Kodak in the UK were advising that the 35mm size film, now known as Internegative Color Film, 6008, should be processed in the Internegative Replenisher plus Starting Solution for best results. The development time was 6 minutes at 75°F, and the rest of the process was identical to Process C-22.

In 1978, a C-41 process type of internegative film came onto the market known initially as SO-406, which became Vericolor Internegative Film 6011, replacing the 6008 film. Kodak in the UK published an informative leaflet in January 1979, explaining how to find the correct filtration and exposure times for the new film using a new “Density Difference” method.

Kodak Internegative Film Type 6110

Ektacolor Internegative Film 6110, front (upper left) and rear (above) labels. The picture shows 10 sheet boxes of 10 x 8 inch Film and 5 x 4 inch Film.

The 5 x 4 box was manufactured about September 1970, with a "Develop Before" date of June 1971. The 10 x 8 box has a develop before date of June 1979.

To the lower left are shown two earlier Internegative 6110 film boxes, 50 sheet and 10 sheet capacity.

Ektacolor Internegative Film 6110 was available 50 sheet boxes in the USA in the 4 x 5 inch size from 1972, but this size and box quantity was not obtainable in the UK. Some laboratories in the UK that made 4 x 5 inch as well as 8 x 10 inch internegs purchased the 8 x 10 inch size and cut the film down to make four 4 x 5 inch internegatives out of one sheet. Having cut the large sheet down to four smaller sheets, in a darkroom, the individual sheets had to be “notched” to subsequently assist the printer in deciding which side of the film was the emulsion side.



Ektacolor Internegative Film 6110, in use.


Two internegatives made from 2¼" square (120 film) High Speed Ektachrome transparencies in 1971. For the prints shown here, the film internegatives were scanned and the prints were made digitally but only the colour balance of the prints was corrected. The contrast was not altered.

The internegatives were made (in 1971) by contact printing the whole of the 120 size Ektachrome film, 12 pictures, onto a single sheet of 8 x 10 inch Ektacolor Internegative film.


Processing Kodak Ektacolor Internegative Film
The film was processed in C-22 chemicals apart from the developer. The developer was made up of “Kodak Internegative Replenisher” and “Kodak Internegative Starting Solution”. The Replenisher was supplied in quantities to make 5 US gallons of replenisher solution, mixed from two powder components and one liquid component. The Starting Solution was supplied as a bottle of liquid, one bottle being enough to make 3½ US gallons of working solution.

It was not possible to process Ektacolor Internegative film by increasing the development time per number of sheets of film developed; only a Replenished process would give reliable results.

The developer working solution was made up of:

  1. 710 ml, or 24 fluid ounces (US measure), of water.
  2. The whole contents of 1 bottle of Starting Solution.
  3. Enough Replenisher solution to make a total of 3½ US gallons.

This was the actual solution in which the film was processed. The Replenisher solution on it’s own was used to replenish the working developer.

The development times for Ektacolor Internegative films were 5 minutes for the sheet film or 6 minutes for the 35mm film, and other sizes such as 46mm and 70mm.
The developer was used at 75 +/– ½°F.

The normal C-22 chemicals were used for the remainder of the process with exactly the same times and temperatures as camera sheet film.

The sheet film was generally processed in 3½ US gallon tanks, or 3 gallon tanks in the UK, with an increased agitation rate compared with the camera sheet films.
The 35mm, 46mm, and 70mm films were processed in deep tank continuous processing machines.

The earliest 35mm version “Kodak Internegative Colour Film”, as listed in the “Kodak Professional Catalogue” in the UK for 1963, was processed in the C-22 developer for camera films with a reduction in development time.

When Michael Talbert made his first Internegatives using Ektacolor Internegative 5 inch x 4 inch sheet film, he processed them in the same C-22 developer as for camera films, but used 7 minutes at 75 +/– ½°F. It is possible that the earliest (pre-1964) version of Ektacolor Internegative in sheet form was intended to be developed in the C-22 camera film developer, with a reduction in the development time, as Michael has been unable to find any reference to the special Internegative Replenisher or Starting Solution before 1963.

Kodak Ektacolor Internegative Film 6110, and Ektacolor Internegative Film 6008, were replaced by the Vericolor Internegative fims, 4112 in sheet sizes, and 6011 in 35mm size, at the end of 1978. In 1979, Vericolor Internegative Film 4112 was available in the UK in 4 x 5 inches, 5 x 7 inches and 8 x 10 inches. Type 6011 was available in 35mm x 80 foot rolls.

Internegative Replenisher Solution

A box of Internegative Replenisher solution for Ektacolor Internegative film.
The replenisher was used on it’s own to replenish the internegative developer. A small bottle of “Starting Solution” came with this carton to make the Internegative Developer.

This box dates from 1973. Replenisher and starting solution was only made in the USA by Eastman Kodak Co. at Rochester and could only be used to develop Ektacolor Internegative film. Vericolor Internegative film, from 1979 (see below), was processed in the normal C-41 developer.

As far as is known, the box shown here was the only quantity ever sold.

Vericolor Internegative Films 6011 and 4112
Vericolor Internegative films were originally designed for an exposure range of 1/1000 second to 30 seconds with tungsten 3200°K lamps, but during the 1980s the exposure range was changed to 1/10 second to 30 seconds.

The film could be balanced for exposure and filtration by following the same procedure as for Ektacolor Internegative films (see above). A starting filtration of 30 Yellow, 10 Magenta i.e (30 10 --), was recommended by Kodak,using a trial exposure of about 10 seconds. The Kodak Data sheet E-24 (H) described a technique of balancing Vericolor Internegative films.

They were developed in the normal C-41 process with development times and replenishment rates as for Vericolor II camera films. No special developer was needed. The Vericolor Internegative and Print Films were only intended for laboratory use & processing, not for exposure in a camera.

Above is a picture showing the boxes of four kinds of Internegative film:

i) two different labels for Vericolor Internegative 4114 Type 2. The expiry date on the right hand box is July 1985.
ii) a box of vericolor Internegative 4112. The expiry date is December 1989.
iii) a box of Commercial Internegative Film 4325. A starting filtration of “+10M+30Y” is printed on the back of the box i.e. 10 Magenta, 30 Yellow.
iv) a box of Ektacolor Internegative Film, dated February 1969.


The internegative films were for making negatives from transparencies which could then be printed onto Ektacolor paper.
Kodak Vericolor Internegative Film 6011 (roll),
Kodak Vericolor Internegative Film 4112 (sheet)

The balancing procedure for the Kodak Vericolor Internegative films, 6011 and 4112, was described in the Kodak Data sheet E-24(H).

A densitometer was used to read the lowest and highest densities from a Kodak “Three point transparency guide” exposed on to the internegative film at a trial filtration of 30 Yellow, 10 Magenta with an exposure time of about 10 seconds. A “Three point transparency guide” was a transparent piece of film with three coloured patches, or areas, and three grey density patches, two of which were used to take the red, green and blue density readings.

The low density value readings corresponding to the red, green, and blue densities of the film dyes were subtracted from the red, green, and blue high density value readings to give “Density Difference” values. These three "density difference" values were compared to a table in the data sheet of “Density Difference Aims”. From the information in the data sheet the correct filtration for any batch of internegative film could be calculated by altering the trial filtration until the “Density Difference” values of the trial film were within the Density Difference Aims.

If the red, green, and blue values from a second trial exposure did not come within the "Density Difference Aims", it was suggested that an internegative was made from a correctly exposed well balanced transparency preferably with a substantial area of grey for colour matching, using the new filtration. The best possible print was made from the processed internegative.

The Kodak data sheet included a “Guide for Adjusting Filter Pack” for working out the correct filtration when judging colour casts in the high-light area of the print. Example: If the high-lights were Yellow, the Guide suggested removing 10 Yellow (if a slight cast), or 20 Yellow (if a noticeable cast), from the filtration.

The opposite of this would be to add 10 or 20 Blue, but almost all filtrations were in Yellow and Magenta when using Vericolor Internegative films.

Another trial internegative was made with the filtration change, and any contrast correction could be made at the same time. Contrast corrections were made exactly as on Ektacolor Internegative film (see above). As long as the final exposure was within the exposure limits of the film, the resulting exposure time and filtration could be used for making internegatives from most transparencies. A good final exposure time to aim for was from 8 to 12 seconds.

Vericolor Internegative Film 4114, Type 2
Was introduced in January 1984. It was specifically designed for making internegatives from Kodachrome and Ektachrome transparencies using exposure times from 5 seconds to 20 seconds with a 3200°K light source.

Vericolor Internegative film 4114 Type 2 was not intended as a replacement for Internegative 4112. Kodak “Commercial Internegative Film 4325” replaced Internegative 4114 in 1993 but Internegative 4112 continued to be sold.

Vericolor Internegative 4114 Type 2 film was only recommended for making internegatives from transparencies, whereas Ektacolor Internegative film and Vericolor Internegative film 4112 could also be used to copy coloured art works, paintings, or any coloured flat copy. The contrast was changed in the same way as in making internegatives from transparencies.

4114 Type 2 sheet film was obtainable in the sizes: 4 x 5 inches; 5 x 7 inches; 8 x 10 inches.

Both Vericolor Internegative films were coated onto a Polyester tear-resistant base, the trade name was “Estar Thick Base”.

Kodak Data sheet E–24(T) gives a “Density Difference “ procedure for balancing this Type 2 film similar to the method given above for Vericolor Internegative film 4112,

A densitometer had to be used, but readings were taken from Kodak Photographic Step tablets, (Grey Scales, printed onto a strip of film), and the filtration changes could be read from a table in the data sheet showing plus or minus values to alter the Yellow, Magenta and Cyan filtration values.

The instructions packed in each box of film gave a trial filtration for that particular emulsion number.
Example: Emulsion Number: 4114 – 143 CC40M + CC25Y. Trial filtration was: 40 Magenta, 25 Yellow. A trial exposure time was around 10 seconds.

If the instructions for the film were mislaid, a filtration of 30 Magenta, 30 Yellow provided a good starting point.

Processing Vericolor Internegative Films
All Vericolor Internegative films were processed in C-41 chemicals, either in “rack and tank” processors or in continuous processing machines.

Kodak Commercial Internegative Films
Commercial Internegative Films, 4325 in sheet film format and 5325 in 35mm format, were introduced in 1993.

Both films were designed for making internegatives from Kodachrome and Ektachrome original transparencies, or for photographing coloured originals on an opaque base, or for copying photographic colour prints. Kodak Vericolor Internegative film, 4112 (see above), was recommended for copying maps and flat artwork.The balancing procedure for both films was described in the Kodak technical data sheets E-225T. Four methods were given for finding the correct filtration and exposure.

  1. The curve plotting method as described for Ektacolor Internegative Film.
  2. The “Lab Aim” method, used only for changing from one batch of film to another. This was essentially the same as method 1, where the characteristic curves from a new emulsion, (new batch of film), were compared to an existing emulsion, (old batch of film). From the differences in the horizontal displacement of the curves a filtration could be calculated for the new batch of film.
  3. The “Density Difference” method. This is described above for Vericolor Internegative films. A slightly different but faster Density Difference procedure was used for Commercial Internegative films and a guide for adjusting the filter pack, or filtration was given to balance the high light to shadow colour. The overall contrast could be changed by varying the exposure in a similar manner to the Vericolor films.
  4. Kodak Internegative Balancing Software (KIBS), Series 2.0, could be used on personal computers or Apple Mackintosh Hardware. Densitometers were also able to be connected to personal computers to eliminate most manual balancing operations.

The film was intended for use with a 3200°K light source (enlargers with colour heads), at exposure times of 1/10 second to 30 seconds. A first trial exposure would have been about 10 seconds using the suggested filtration printed on the label of the Internegative film box. The Data sheets also gave a starting filtration of 30 Magenta, 30 Yellow.

For photographers using the film for the first time, the Data sheets gave details of working out a “Starting Exposure” when using an enlarger to make internegatives. An exposure time of 10 seconds was suggested for the sheet film 4325 when the illumination at base board level without any filtration dialed in the colour head was 32 Lux, or 3 Foot Candles. An exposure for the 35mm film was 1 second with 323 Lux, or 30 Foot Candles.

A separate exposure meter could also be used to determine a starting exposure, or the exposure meter in a single lens reflex camera when using the 35 mm film. If the meter was set to 400 ISO (ASA), the correct exposure would be 1/8 second at F5.6. This exposure would apply to the sheet film and the 35mm film.

Both types of film were processed in C-41 chemicals, using the same timings and procedure as the camera films.

Commercial Internegative Film 4325 was obtainable in sheet format in 1999 as:
4 x 5inches in 10 and 50 sheet boxes.
8 x 10 inches in 10 sheet boxes.
By 2003, the only size available for sale was 4 x 5 inches in 50 sheet boxes.

In 1999, Commercial Internegative Film 5325 was obtainable in 80 foot lengths in 35mm format. By 2003 the length had increased to 100 foot in the same format.

These were the last Internegative films made by Kodak. As far as is known the manufacture of both formats ceased in 2006.


The images below were sent to Michael Talbert by Russ Chapman, living in Melbourne, Australia.

They are Kodak Internegative 5235 cross-sections. The measurements on each image (44.9microns left and 46.2microns right) are the swollen section dimensions (swollen in water) and would be about 200% more than an unswollen section. They were produced in 2005, shortly before the film was discontinued.

Russ says "Note the unusual emulsion arrangement. The additional magenta layer between TWO cyan emulsions (see processed image, RHS below). This was to provide additional interimage effects to enhance the colour reproduction characteristics of what was a quite complex emulsion of the time."

Raw Emulsion

The image below shows a box of Ektacolor Internegative Film and a box of Ektacolor Print Film.
The expiry date on the Ektacolor Print Film box is “January 1967”. Most types of Kodak Colour Sheet Film had an expiry date of one year from manufacture.

Ektacolor Print Film

Eastman Kodak introduced Ektacolor Print Film in 1950 to produce colour transparencies from the camera films (i) Ektacolor Type B colour negative sheet film and (ii) Kodacolor roll film negatives, for use in displays and where transparencies and paper prints were desired from the same subject.

“Duplicate” transparencies of any size could be made on Ektacolor Print Film. Any number of duplicates could be obtained and the results on Print Film were far better than trying to duplicate an original Ektachrome or Kodachrome transparency onto Ektachrome Type B sheet film. No sheet films specifically for duplicating colour transparencies were manufactured by Eastman Kodak until 1966 (see Ektachrome Duplicating Films).

The film was intended to be exposed in enlargers, notably the “Kodak Auto-Focus Enlarger, model E”, a Kodak enlarger listed for sale in “Kodak, Products for the Professional”, an Eastman Kodak catalogue dating from 1949. The Data sheet for the film advised that a heat absorbing glass and a UV filter should be fitted to any enlarger used for exposing Ektacolor Print Film. The film was balanced for a colour temperature of approximately 3200°K.

Colour balance was varied by means of Kodak Color Compensating Filters (CC), or the later Kodak Color Printing Filters (CP), or a colour head fitted to a black and white enlarger, such as an Agfacolor head, or a purpose built colour enlarger (Agfa Varioscop 60).

Chronology of Ektacolor Print Film

Film No. as printed on side of Box

Date Introduced

Safelight Wratten Series No.

Suggested Trial Exposure Time, secs

Development Process

Code Notch




10 - 20

Ektacolor Process Kits

3 Semi-Circles


1956 ?


10 - 20

Ektacolor Process B-41 OR
Process C-22
2 Narrow Vs and 2 Wide Vs


10; 10H (UK)

20 - 40

Process C-22
3 Wide Vs

2x the speed of 6108

10; 10H (UK)

10 - 20

Process C-22
3 Wide Vs

4109; "Estar" Thick Base

10; 10H (UK)

10 - 20

Process C-22
3 Wide Vs


  1. Although Ektacolor Print Film was in use by Eastman Kodak in 1950, it may not have been put on sale to the general public until 1951.
  2. The early type of Print Film dating from 1950 was marketed in various “camera sized” sheet films, from 2¼ x 3¼ inches to 11 x 14 inches with larger sheets available to special order. Roll sizes were obtainable up to 39 inches wide by 100 foot long. In 1960, 7 sizes of sheet film were being sold in the USA ranging from 4 x 5 inches to 20 x 24 inches in boxes of 10 sheets. Additionally, the 8 x 10 inch size was available in boxes of 50 sheets.
  3. The film could be handled under a safelight fitted with a Wratten Series 7 filter and a 15 watt bulb (possible UK equivalent was a 25 watt bulb), for about 5 minutes. The Series 7 was a Green filter, also suitable for use with Infra red sensitive materials.
  4. Ektacolor Print Film is believed to have first been used by Eastman Kodak in 1950. A photographic exhibition was held by Eastman Kodak in the Grand Central Terminal Station in New York in 1950. One of the main features of this exhibition was a giant transparency 18 feet high by 60 feet long made in sections on Ektacolor Print Film.
    The transparencies were changed every three weeks, the first one being exhibited on May 15th 1950. Because there was no negative size which would produce a sharp image at that print magnification, Eastman Kodak built a special camera taking 8 inch x 20 inch sheets of Ektacolor film, later Ektacolor Professional film. In the 1960s* (and probably in the 1950s also), the negative was printed onto strips of Print Film 18 feet high x 19 inches wide, with 40 strips of Print Film making up the whole transparency. A ½ wide strip of the negative was printed onto each strip of Print Film. After joining the strips together with transparent tape, the giant transparency was rolled onto an 18 feet wide spool. At the Grand Central Station the spool was hoisted into position, and the bottom end of the spool unwound by traveling on a small “truck” on rails which moved forward unwinding the transparency for the whole 60 foot length. The transparency was illuminated from behind by over a mile of cold cathode tubes.
    *Ref: “The Third Here’s How”, an American Eastman Kodak publication, Jan 1966.
  5. A data sheet for Ektacolor Print Film was first included in “Kodak Color Films” booklet, published in November 1951.
  6. Author's Note. If Eastman Kodak had made 8 inch x 20 inch sheets of the earliest Ektacolor film, the film emulsion would have been balanced for Tungsten light, (Ektacolor Type B film). For daylight exposures, the photographer could have used a converting filter over the lens, or the colour balance could have been altered in the colour printing operation. The first option would have produced the best colour balance. With an 85B conversion filter over the lens, the film speed was altered from 8 ASA (ISO) to 5 ASA (ISO).
  7. Vericolor Print Film 4111 “Estar” thick base was introduced in 1978 for Process C-41.

Exposure and Processing of Early Print Film - 6105 thr' 6108
The film was designed for exposure times of 10 seconds (normal) to 120 seconds. Because of unavoidable differences in speed and colour balance between each batch of film, a supplementary data sheet giving filter suggestions for exposure times of 10 seconds and 120 seconds was enclosed in each box of film.

An exposure time of 10 to 20 seconds was recommended as a “starting” exposure time. As each batch of Print Film varied in speed, the supplementary data sheets also suggested a “lens opening adjustment” for altering the exposure time when changing from one batch of film to another. This was noted on the sheet as “Decrease Exp. ½ stop”, or “Increase Exp. 1&2/3 stop”. The filtrations given were generally used to calculate the new filtration when changing between batches of Print Film rather than using the filtration figures as a “starting filtration”.

Kodak had already allocated the Type Number 6106 to Ektacolor Type L film (in 1958) and 6107 to its Commercial Ortho black and white film. Hence, the next Print Film became 6108, introduced in 1960.

The recommended “starting exposure” time had increased to 20 to 40 seconds. About the same time the Wratten Series 7 safelight filter recommendation was changed to a Wratten Series 10, or 10H (for the UK) filter. This was “dark amber”, or a very dark orange colour. The film could be handled under this filter for about 5 minutes at a distance of about 4 feet from the safelight.

In the mid-1970s, the minimum exposure time recommended for Ektacolor Print Film 4109 had been reduced to 1 second. The exposure time range was now 1 second to 120 seconds.

The earliest type of Print Film was processed in the “Kodak Ektacolor Processing Kits”, available in 1 and 3½ gallon sizes, later known as the B-41 Process. After 1955, it was possible to process the Print Film in the (then) new C-22 process, as used for the new Ektacolor Type S sheet film. Either process could be used, and minor colour balance differences between the two processes could be corrected by altering the filtration. By 1958 the B-41 process had become obsolete and from then on Ektacolor Print Film was processed in C-22 chemicals.

It was possible that the C-22 development time for Print Film prior to 1960 was 14 minutes at 75°F. The instruction sheets after this date (Type 6108) recommend 12 minutes at 75°F. The times in the rest of the solutions and washes were identical to the process times for Ektacolor and Kodacolor films. When processing in the “Ektacolor Process Kits”, Ektacolor Print Film and Ektacolor Type B film could be processed together, but the first three steps had to be carried out in total darkness, not under the Wratten Series 7 safelight!

An Ektacolor Print Film box Type 6105, dating from 1955. The “Dev Before” date printed on the back of the box is April 1956. This is the first type of Ektacolor Print Film, as introduced in 1951 for processing using the Ektacolor Processing Kit.

Above is shown the rear label, which has the “code notch” used from the film’s introduction in 1951. The earliest Ektacolor Processing Kits, dating from 1949, contained instructions and processing times for a 68°F process. In 1950, the processing temperature was raised to 75°F, and from this date Eastman Kodak advised that Ektacolor Type B film should, if possible, be processed only in chemical kits designed for use at the higher temperature. This label suggests that Ektacolor Print Film should similarly only be processed at 75°F.

An Ektacolor Print Film box dating from 1961. The “Dev Before” date printed on the back of the box is January 1962. Its Type No. is 6108. Print Film Type 6108 was introduced in 1960.

In 1960, the recommended safelight filter had been changed to a Kodak Wratten Series 10 (dark amber). There was a new “code notch”, and the C-22 process had replaced the earlier Ektacolor Processing Kits.

Ektacolor Print Film ~ Later Type - 6109
In March 1963, Ektacolor Print Film was increased in speed (twice as fast as the previous film) by the introduction of Type 6109, with a price reduction of 20% compared with the prices of the previous 6108 film.

It was recommended that the film should be handled in total darkness, but a safelight with a 15 watt bulb (English instructions state 25 watt bulb) fitted with a Kodak Wratten Series 10 filter could be used at a distance of 4 feet as long as the film was exposed to the direct light of the lamp for no longer than 30 seconds. In the UK instruction sheets, the safelight filter was known as “Wratten 10H” (dark amber), but the filter was identical to the Wratten Series 10. The “No.13” Kodak Safelight filter (amber), introduced in 1973 and intended for use with, at that time, Ektacolor 30RC and 37RC papers and later colour printing papers, was not safe to use with Ektacolor Print Film.

The sensitivity of the 6109 film was approximately equal to Ektacolor Paper, although Ektacolor Paper could be handled under the same safelight for a much longer time, about 4 minutes.

The film was balanced for 3200°K lamps and, similar to the previous film, supplementary data sheets were enclosed in each box giving filtrations for exposure times of 10 seconds and 120 seconds.

Filtrations for Ektacolor Print Film were similar to those on Ektacolor papers, but most negatives required a higher magenta filtration compared to the colour papers. If a certain negative had made a successful print on Ektacolor paper, its filtration would make a good starting filtration for a transparency on Ektacolor Print Film, with a “stepped test” exposure on the film. The film was generally about half the speed of the printing paper.

Test transparencies appeared much too reddish~magenta whilst wet, and colour balance and exposure could only be successfully assessed when the film was completely dry.

The film was not completely “clear”; it had a slight opaque appearance compared to an Ektachrome transparency. This created a “diffuser” effect when viewing a Print Film transparency.

In 1970, Michael Talbert made some 2¼ inches square transparencies by contact onto Print Film. The transparencies were intended for projection but, when projected onto a white wall, they gave an odd, diffuse, unsharp image compared to High Speed Ektachrome film transparencies. He came to the conclusion that transparencies made in this way were not suitable for projection; Ektacolor Print Film transparencies were only acceptable for display purposes, where they could be illuminated from behind.

Later, when making some 11 inch x 14 inch Ektacolor Print Film transparencies on a Beseler enlarger using Kodak Colour Printing (CP) filters inserted into the filter draw, he found that when he changed the exposure time, the colour of the Print Film also changed. To alleviate this problem, he altered the exposure by the lens aperture when the test prints were very close to the correct colour i.e. keeping the exposure time constant. He used this method of altering the exposure because of his lack of experience of making Print Film transparencies at that time (1971). But, with more experience, he became adept at filtering out the slight change in colour when changing exposure times.

Ektacolor Print Film emulsions were coated onto a thick, acetate base, approximately equal to the thickness of a sheet of Kodak black and white sheet film before sheet films were coated onto an “Estar” polyester thick base. In 1971, the base of the 6109 Print Film was changed to a similar (Estar thickness) base, which was thinner than the acetate base. It then became 4109 Print Film.


Ektacolor Print Film and Vericolor Print Film boxes

The Vericolor Print Film boxes date from the 1980s, the expiry date on the 4 x 5 inch Vericolor 4111 Print Film box is “August 1985” and the larger Vericolor 4111 Print Film box is dated “October 1982”. Vericolor Print Film 4111 was only manufactured and packed in the USA.

The Ektacolor Print Film boxes on the left hand side have expiry dates of “January 1967” and “December 1968”. This type of box was in use from 1966 to 1970 for film manufactured in the USA and then packed in the UK for the UK market. Print Film manufactured and sold in the USA was packed in “picture in a darkslide” design boxes, as shown by the middle box. All these Ektacolor Print Film boxes are of the later type of film, 6109.

On the right hand side is a 5 x 7inch size box of the earlier, slower speed type of Print Film, now Type 6108 (the earliest Type 6105, had been renumbered as 6108 by this date), with an expiry date of “January 1962”, printed on the rear of the box.


A box of Print Film manufactured in the USA for sale in the USA:

This box dates from the mid 1960s, with a “Develop before” date of November 1967, see the central 4" x 5" box in the large picture above. It was manufactured in the USA for sale in the USA only.

The instruction sheet and the supplementary data sheet were both printed in the USA.

A box of Print Film manufactured in the USA but intended for the UK market:

This Print Film was imported into the UK and then repacked for the UK market.
The “Develop before” date is December 1968 and is the box shown in the large picture above, on the left hand side with “Colour Film” printed in red in the darkslide. Importing Ektacolor Print Film from the U.S.A. started in 1965 and finished in 1970. Ektacolor Print Film and Ektachrome E3 sheet film were the only sheet films to be repacked for the UK market. It is not known why this was done.

The Print Film instruction sheet and the supplementary data sheet were both printed in the UK.
Ektacolor Print Film - 4109

Above is shown a box of Ektacolor Print Film type 4109.
It has a "develop before" date of December 1977 in Process C-22.

To the right is the rear label of the Ektacolor Print film. The type 4109 had been coated onto an Estar Thick Base (0.18mm) since its introduction in 1971. The older emulsion, type 6109, was coated onto an acetate base which was slightly thicker, but otherwise the films were identical.

Kodak Vericolor Print Film - 4111
Kodak Vericolor Print Film 4111 (sheet) was designed for making large display transparencies from colour negatives and internegatives. It had a thick base and a matt surface to facilitate retouching and was available in sheets and wide rolls. It replaced Kodak Ektacolor Print Film.

Kodak Ektacolor Slide Film

Introduction ~Type 5381 and (Later) Type 5028
Ektacolor Slide Film was introduced in the USA in 1961 as a 35mm film designed for making 35mm transparencies from colour negatives. It had no diffuse “matt” layer and produced a completely clear base after processing.

Although the film was first introduced in 1961, Kodak had manufactured “colour print films” for the motion picture industry for many years previously. Eastmancolor Print Film Type 5381, used for making cinema projection 'prints' from Eastmancolor negative 35mm cine film stock, was marketed as long ago as 1950.

In the late 1950s, Kodak in the USA were offering to make Kodacolor transparencies from Kodacolor negatives in standard sizes, mainly 35mm, onto a film very similar to (what became) Ektacolor Slide Film.

In the UK, Ektacolor Slide Film was first listed for sale in the Kodak Professional catalogue for 1964-65, obtainable in 100 foot lengths of 35mm film. It sold at a slightly lower price than the equivalent length of Ektacolor Professional film, Type S. The base thickness was about equal to 35mm colour negative film, much thinner than Ektacolor Print Film.

The film could be exposed by contact printing, or by projection printing in enlargers, or in various printers such as the “Bowens Illumitran”, Homrich internegative and duplicating printer, plus others. Kodak recommended exposure times of ¼ second to 8 seconds in tungsten light. The film was also available to special order in large sheet film sizes and wide rolls, mainly for colour printing laboratories. The author remembers exposing the film at much longer times than 8 seconds when making 8 x 10 inch transparencies on the sheet film version. The film was processed in Process C-22 chemicals, with a development time of 17 minutes, the remaining solution times were exactly the same as when processing Kodacolor roll film or Ektacolor Professional sheet film.

Ektacolor Slide Film 5028 first gets a mention in the Kodak “Trade Circular” for December 1963 as a new product in the UK “Kodak Ektacolor Slide Film will be available in 35mm x 100 ft. rolls, at a cost of £12 3s 10d.” The film was likely to have been obtainable in early 1964.

By the end of the 1960s it had gained the number 5028, and in the early 1970s it could be additionally obtained in 8 x 10 inch boxes of 10 sheets of film. It was also available in boxes of 15 x 12 inch sheets and wide rolls to special order. These sheet films were identical to the 35mm film.

The Slide Film was handled in the same safelight conditions as Print Film 6109 and 4109.

The boxes of Slide Film had no instruction sheets or data sheets enclosed with the film. Having made 10inch x 8 inch transparencies on this film from Ektacolor sheet film negatives on a De Vere enlarger fitted with an Agfacolor head, Michael Talbert can say that the filtrations were similar to Ektacolor Print Film.

Kodak Vericolor Slide Film 5072
Kodak Vericolor Slide Film 5072 (roll) was designed for making 35mm and 46mm transparencies from colour negatives and internegatives. The film had a thin, clear base and was available only in rolls, 35mm and 46mm wide. It replaced Kodak Ektacolor Slide Film. Vericolor Slide Film was initially available as “SO-372”. An “SO” numbered product meant that it could be withdrawn at any time without warning and there was no guarantee that a similar product would replace it. 5072 was most likely an improved version of SO-372.

Processing Ektacolor Print and Slide Films (After 1955)

Ektacolor Print and Slide films were processed in C-22 chemicals, but the developing times were different to the camera sheet, roll, and 35mm films.

Print Film required 12 minutes development and Slide Film required 17 minutes development at 75°F. These times date from 1960 for Print Film and 1969 for Slide Film but pre-1960 Print Film required a development time of 14 minutes. Later processing sequences, dating from the mid-1970s, suggested development times of 11 minutes for Print Film and 16 minutes for Slide Film. The remaining steps for the sequence were identical to the sequence for camera films.

Ektacolor Print Film Additive (from 1964)
By mid 1964 it was noticed that the increased speed Type 6109 of Ektacolor Print Film suffered from “pre-exposure” problems or, to put it another way, the film didn't keep well in storage. This was improved upon starting with the emulsion batch number 101. It was then found that the improved film emulsions were having a detrimental effect on the C-22 developer solution and therefore it was necessary to mix an additional solution into the C-22 developer after the Print Film had been processed to keep the developer within a satisfactory operating standard. Ektacolor Print Film Additive compensated for the effect on the chemical balance of the C-22 developer when processing Ektacolor Print film when the same developer solution was used for Kodacolor X and Ektacolor Professional films.

Ektacolor Print Film Additive was made available in the UK from August 1964 in four US fluid ounce bottles priced at 13shillings (65p) per bottle. By April 1965 the price had dropped to 9shillings and 6oldpence (about 48p) per bottle.

In a replenished C-22 process, when processing Ektacolor Print or Slide film, Ektacolor Print Film Additive was mixed with the C-22 developer. The purpose of the Additive was to compensate for the effect of the Print Film or Slide Film on the chemical balance of the developer. The Additive was packaged as a liquid in 4 US fluid ounce bottles. It was diluted to a stock solution which was mixed with the C-22 developer at the rate of 1% of the total volume of C-22 developer replenisher being used for each batch of Print or Slide Film processed. This was equivalent to 3¼ ccs for every square foot of film processed, or approximately 3¼ ccs for every two sheets of 8 inch x 10 inch Print Film.

As an example: Add Replenisher plus Additive to the developer after processing each batch of Print Film. The replenishment rate was 325ccs of developer replenisher to be added to the developer for each 1 square foot of Film processed. Hence, having processed 4 off 8 inch x 10 inch sheets (or 16 off 4 inch x 5 inch sheets):
Area of 1 off 8 inch x 10 inch sheet = 0.56 sq.ft. Hence, 4 off = 2.24 sq.ft. Hence, 2.24 x 325ccs = 728ccs;
Then, 1% is 7.28ccs.
So there is need to add 728ccs of Replenisher plus 7.28ccs of Additive to the C-22 developer.

In an unreplenished C-22 process, such as when processing sheets of Print Film in dishes, the 'Unit 1' 2litre size C-22 Process component containing the Developer and Stop Bath (see picture of box above), would process at least 12 sheets of 8 inch x 10 inch Ektacolor Sheet Film (6,450 square cms) before exhaustion, but only 2½ sheets of the equivalent area of Print Film before exhaustion (1,290 square cms).

The rest of the solutions in the 2litre kit, i.e. the 'Unit 2', would process at least 24 sheets of 8 inch x 10 inch Ektacolor Films, including Ektacolor Print Film (12,900 square cms).

For processing the Print and Slide Film on a regular basis, Kodak recommended a replenished C-22 system for best results. It was not advisable to develop the films giving “time compensation” with the development time, as used with the smaller C-22 kits when processing 35mm and roll size Kodacolor (X) films. Nevertheless, an article on the processing of Ektacolor Print Film by Ernest Gehret, published in the British Journal of Photography Almanac of 1960 (and in later Almanacs/ Annuals), gave time increases with increasing exhaustion of the C-22 Developer for up to 12 sheets of 4 inch x 5 inch Print Film processed in 1litre of developer. Gehret suggested times of development of 14 minutes for the first three sheets, to 16½ minutes for the last three sheets. The time increases for development were for the 6108 type of Ektacolor Print Film where the Additive was not required.

Ektacolor Print Film Stabilizer
Introduced into the UK in November 1963, Ektacolor Print Film Stabilizer was obtainable in a single solution concentrate as 7 US gallons of Stabilizer Replenisher, or it could be diluted to make 8.75 US gallons of working solution. The liquid stabilizer was imported from Eastman Kodak Company, USA.

Its use was recommended for all display transparencies where it gave a significant improvement in dye stability of the yellow and magenta dyes of Ektacolor Print Film. The Stabilizer treatment replaced the one minute 'Photo Flo' rinse step at the end of the process, and transparencies were given 1 minute treatment time at 73–77°F before drying.

The concentrate was diluted with six parts water to make a stock replenisher solution, and four parts of the stock solution were further diluted with one part water to make the working solution. The replenishment rate was 80 ccs of replenisher to 1 square foot of Print Film processed.

In 1978, Ektacolor Print and Slide Films were replaced by Vericolor Print Film 4111, and Vericolor Slide Film 5072, designed for the C-41 Process.


Processing Ektacolor Print Film 6109 and 4109 in the Kodak 30A Rapid Processor
It was possible to process large sheets of Ektacolor Print Film in the Kodak 30A processor using the Replenisher solutions of C-22 chemicals. For processing the Print Film, it was recommended to use the later type of processing tubes (drums) where the “spiral liner” prevented the Print Film from sticking to the inside surface of the tube (drum).

Seemingly, the total processing time, working at a temperature of 75ºF, was 15 minutes. The large difference in the total time of 15 minutes compared to the normal processing time of 51 minutes at the same temperature was made possible by using the replenisher solutions instead of the working solutions, and by continuously agitating the Print Film in each solution. In general, replenisher solutions are two thirds stronger than the working solutions. In addition, Ektacolor Print Film Stabilizer was used as a final bath, instead of the usual Photo Flo rinse, which gave more stability to the yellow and magenta dyes.

In the UK, in 1973, the Kodak Rapid Processor Model 30A was supplied with one 3040A processing tube (drum), one 2024A processing tube (drum), and one processing tube adapter for prints smaller than 20inches x 24inches. A timing disc was also supplied for timing the processing sequence when processing Ektacolor 37RC paper.

The Eastman Kodak catalog for the USA gives more information about the 30A processor. There were 10 solution containers, a self contained 100ºF thermostatically controlled water bath, and two timing discs for Ektacolor 37RC paper, one for 50Hz power supply, and one for 60Hz power supply, plus the two tubes (drums) and adapter.

The 100ºF water bath could not be used when processing Ektacolor Print Film, and the operator had to provide his own supply of thermostatically controlled water at 75ºF.

There were no timing discs for Ektacolor Print Film and the operator had to time each solution and wash with his own timing device.

When processing the Print Film, five additional solution containers were required for use with the 3040A tube (drum) and two additional containers with the 2024A tube (drum). It is possible that some or all of these containers were used for the final wash.

In the description of the Kodak Rapid Processor Model 30A in the 1973 Kodak Professional Catalogue for the UK, there is no mention that the machines could also process Ektacolor Print Film. By 1980 the 30A had been withdrawn from the catalogue and was no longer for sale in the UK.

Michael Talbert sends his many thanks to Richard Frieders of the “Photographic Society of America” (P.S.A) for finding and sending various articles from past P.S.A. Journals concerning Kodacolor film and other information relating to colour negative materials.

Michael Talbert started making colour prints in 1969, using Kodak Ektacolor Commercial paper. He was a photographic colour printer in the 1970s, printing colour negatives mainly onto Agfacolor paper. He also had experience using about 10 types of Kodak paper, plus other makes, Gevacolor, Fuji, Paterson, Konica.

Michael now sets up and takes “Retro” fashion pictures, but prints them digitally.

This page last modified: 6th July 2020