From: Richard Knoppow (dickburk@ix.netcom.com)
Date: 09/08/01-07:11:53 PM Z
At 03:24 PM 09/08/2001 -0400, you wrote:
>on 9/7/01 10:46 PM, Richard Knoppow at dickburk@ix.netcom.com wrote:
>
>>>
>>> Technicolor is a very large player in the printing and distribution end
>>> of the business. Perhaps they are now the largest.
>>>
>> I don't know if they are the largest. The big guys are Technicolor,
>> Deluxe, CFI. all of whome make many thousands of prints every day.
>>
>
>Technicolor owns CFI. I think Deluxe is independent.
>
>In any event, I was always interested in the early techicolor recipe using
>pyro. Anyone know where I can find it?
>
>Toshiaki Ozawa
>NYC
>
Technicolor's processes were highly proprietary. I doubt if actual
formulas were ever published. The patent literature may have some clues but
hundreds of patents were issued to Technicolor over the years.
I tried to find formulas for some tanning developers. Its surprizingly
difficult, none of my usual sources have any. I think the formulas for the
Kodak Wash Off Relief process were published and perhaps also for its
successor, the Dye Transfer Process, which is essentially similar. Both are
very similar to the Technicolor IB process. In fact, Kodak made all the
photographic material for Tech.
I did find some example formulas in _History of Color Photography_ Joseph
S. Friedman, Phd, 1944, Boston, The American Photographic Book Publishing Co.
I believe there is a reprint edition of this book.
In any case, Friedman has a great deal of stuff on Technicolor (for whome
he worked at one time) and quotes some sample tanning developers, not
necessarily those used by Technicolor. He quotes E.J.Wall (who also worked
for Technicolor, but much earlier).
Formula No.1
Metol 1.5 parts
Hydroquinone 1.5 parts
Sodium Sulfite 2.0 parts
Sodium Carbonate 17.5 parts
Potassium Bromide 1.5 parts
Water to 1000.0 parts
No. 2
Hydroquinone 4.0 parts
Sodium Sulfite 2.0 parts
Sodium Carbonate 15.5 parts
Potassium Bromide 1.0 parts
Water to 1000.0 parts
Friedman also quotes a Technicolor patent, USP 1,919,673
Pyrogallol 8.0 parts
Sodium Hydroxide 3.0 parts
Ammonium Chloride 1.5 parts
Potassium bromide 1.5 parts
Citric Acid 0.2 parts
Water to 1000.0 parts
There are almost certainly better practical formulas.
The wash-off relief process, and the dye transfer process use a bleach to
produce the tanning effect. The matrix was developed in a normal active
film developer like DK-50 and bleached in an acid dichromate bleach
containing a halide (chloride). The resulting film was then "developed" in
hot water to produce the relief image. There is more to it than this but
this is the essential.
Its possible that Technicolor used this sort of indirect tanning rather
than a direct tanning developer. Unfortunately, the retired Tech people I
knew are all dead so I have no one to ask.
There have been attempts to resurect the Kodak Dye Transfer process. I
don't know if anyone is making materials now.
Its very likely that the actual Dye Transfer formulas are available, I
just don't have them. Someone on this list may have formulas or even be
using the process.
---- Richard Knoppow Los Angeles,Ca. dickburk@ix.netcom.com
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