Pinatype dyes identified
Prof. John Wall in "Practical Color Photography" (1922 available online), on pp. 77-79 discusses the process and identifies the dyes used in the Pinatype dye transfer:
RED- natural carmine; lanafuchsin BB or SL;
BLUE- indulin blue for blue;
YELLOW-acid yellow, mikado yellow, or quinoline yellow.
Carmine is of course a well known colorant obtained from insects, C.I. 75470, aka Natural Red 4. (See first attached file thumbnail and also http://en.wikipedia.org/wiki/Carmine). It is likely that this is the dye used in Pinatype because the Pinatype dye and carmine both had to be mixed with ammonia before it was mixed with water and used. It is pink in color and would serve for the magenta.
Lanafuchsin BB has Colour Index number C.I. 16630 with this chemical description: 3-[(5-Acetylamino-2-methylphenyl)azo]-4,5-dihydroxynaphthalene-2,7-disulfonic acid disodium salt. There are illustrations of similar chemical structures, see Acid Violet 6, C.I. 16600.
Indulin blue, aka Acid blue 20, c.i. no. 50405. The structure is the second attached graphic.
Quinoline yellow, aka Food Yellow 13, D&C Yellow No. 10, Acid yellow 3, Quinidine Yellow KT, Japan Yellow 203, Lemon Yellow ZN 3, C.I. 47005
The structure is pictured in the third graphic.
I imagine that the first set of Capstaff Kodachrome dyes were similar in character.
What kind of company are hinting at?
Originally Posted by falotico
Indulin blue fails the test of being a sulfonic acid. It has amino groups terminating it and thus is sold as the salt of an acid rather than being the acid itself. IDK how it would transfer compared to the other 2 dyes in the reference given which are sulfonic acids.
It would be nice if all of these dyes were azo dyes as well. Thus we could use one dye set for DT and DB imaging.
Companies making color film
There were a wide variety of small companies who developed a color photographic process, particularly for movies. Usually they bought their raw stock from Kodak because EK was required by law to sell to its competitors, otherwise the government would sue EK for an anti-trust violation. All the classic Technicolor films, "Gone With the Wind", "The Wizard of Oz", "Snow White and the Seven Dwarfs", "Singing in the Rain", etc. were printed on Kodak release prints. Technicolor had developed a technique of dying a black and white release print into a full color release print. Technicolor did this for two reasons: 1) It wanted to be sure its release prints would run through a standard projector as well as a typical black and white film; 2) Technicolor used the same sound track as a black and white film. Typically Technicolor would print the sound track on black and white EK stock then DT the colors afterwards.
In the silent film days Technicolor appears to have manufactured its own film. The 1926 color film "The Black Pirate" with Douglas Fairbanks was shot with a special camera which recorded two-colors, called red and green, one every other frame. The camera negs were then step printed on to 70 mm stock, red images along the right side and the green along the left. The film was processed in some manner (relief matrixes? dye mordants?) and then the right side was dipped in a trough full of red dye and dried; then the left side was dipped into green dye and then dried. Next the 70 mm film was folded in half down the middle so the green image would overlay the red image in register. The two sides were glued together to form a 35 mm film which was run through the projector. Unfortunately, the film would peel apart and jam the projector. For this reason Technicolor developed the DT method.
In the silent era some companies hand painted their films; some used stencils; some used a rotating color wheel with red and green filters which rotated in synchronization in front of the projector lens. When sound came in some companies used a "bi-pack" camera, sandwiching two pieces of film face to face and running them through the camera as if they were a single piece of film. The front element was transparent and dyed yellow. It was sensitive to blue light but let red and green light pass through to the rear piece of film. Fox Studios produced such an experiment in 1929(?) which I saw: it was printed in blue and a ruby red--very natural. The Marx Brothers appear in a rare two-color process (on Youtube?) That would have been Paramount Studios. Brewster Color used dye toning; some examples of cartoons are on Youtube. Gaspar Color used a dye bleach method. He lacked a camera which would take separation negs, so his only US work is in stop motion, the "Puppetoons"--the most famous is "Tubby the Lonesome Tuba". This was a three-color process. I think Gaspar might have had his film manufactured in Europe. I don't believe he used EK materials.
Wikipedia has a good discussion of color cinema companies.
Pinatype dye structures
Capstaff's patents for his two-color process call for an "acid dye (preferably the salt of a sulfonic acid)", US 1196080; US 1315464. Only the dyes which you cited fit this description: lanafuchsin & quinoline yellow. The dyes carmine and indulin blue clearly are not sulfonic.
Pinatype dyes were used to dye the planographic matrixes over and over again. The matrixes could produce as many as twenty prints. The presence of aniline groups in indulin blue and the lack of SO3 groups in it and carmine indicate that these dyes diffuse more readily out of gelatin than dyes with more SO3 groups, groups which would have the effect of binding more substantially to the gelatin.
The Capstaff process was for "one off" assemblies of transparencies. While a dye transfer to blank paper over a period of ten to fifteen minutes would preserve the highlights, Capstaff required that the gelatin be thoroughly dried before dying, (Wall recommends drying for as long as three hours). A print surface so dried would be harder and much more likely not to absorb dye in the tanned highlights; even dyes with more affinity for gelatin such as salts of a sulfonic acid. It is possible that a wide variety of azo dyes which are salts of sulfonic acids would work in the Capstaff process. So a set of dyes suitable for DT and DB might be found.
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Gaspar had a special colour seperating cine-camera made. However it took three colour-separations in high-speed succession, what nevertheless hampered filming fast moving objects. Added by the low speed of that colour film system.
Originally Posted by falotico
During Gaspar's European period hat silver-dye-bleach film was made by Gevaert.
Last edited by AgX; 01-30-2013 at 06:27 AM. Click to view previous post history.
I am aware of those processes and patents. I was pointing out that Indulin Blue is not a sulfonic acid dye and therefore was probably not one that Captstaff really used. I also point out that a DB and a DT system could be built using the same dyes if they were all from the Azo dye family.
A multi-use set of Azo dyes both for DB and DT would be very convenient. It might also be possible to combine the two processes: develop with a tanning developer, let the dye transfer into the whole matrix approximating the correct tones, and then bleach out the highlights.
From the language of the patents Capstaff seems to indicate that he uses only one dye per color. It also seems that his images from Capstaff Kodachrome were all assemblies requiring silver halide emulsions on transparent bases. I recall seeing a two-color portrait of George Eastman(?) from the 1920's which was published in the Time/Life book on photography called "Color", (1978). That gives some idea of the color values; the warm tones were somewhat orange. Looking through samples of dyes available at that time with the correct chemistry (acid dyes which form salts of sulfonic acids) it might be possible to rediscover the dyes that Capstaff used. The Colour Index gives structure, hue, lightfastness and date of discovery.
Capstaff invented two versions of DT: the first tanned the highlights with a bi-chromate bleach in the standard manner; the second tanned all the gelatin with ferric chloride and tartaric acid and then de-tanned the lowlights with a UV light image. I assume each version used different dyes. IDK which version the portrait in Time/Life "Color" used. I would love to see a Capstaff DT in the flesh.
I have seen examples of European Gasparcolor on Youtube. Gaspar moved here to California before the war and lived in Beverly Hills. He donated all his papers to UCLA and these are held by Special Collections. I wonder if he had Gevaert coat his films after the war. IDK who did that work for him.
All of the Capstaff work may now be at the George Eastman House.
As for a single dye set for both DB and DT, that is my goal as then you can match the prints using different methods. And, DB and DT materials are rather easy to coat yourself. None are in production at this time, but Jim Browning has posted a formula for the Matrix Film, and I have suggested elsewhere on APUG that a hardened version in a multilayer film or paper might be used for DB.
Jim Browning posts the three dyes he uses for DT along with his formula for matrix film at http://www.dyetransfer.org/. These dyes are:
Acid Blue 45- C.I. 63010
Acid Red 80- C.I. 69215
Acid Yellow 11- C.I. 18820
Only Acid Yellow 11 appears to be an azo dye, but it might be suitable for DB.
All the structures I can find for Chicago Blue are diazo (cf. Chicago Sky Blue 6B- C.I. 24410); the dye for the DB emulsion in "Photographic Emulsion Making" Solantine Pink is also diazo, C.I. 25380. Do the Chicago Blue or the Solantine Pink in this DB method transfer?
If I can get out to Rochester, NY I would like to see what I can at the George Eastman House.