Improvements relating to the Preparation of Coloured Plates for Obtaining Coloured Representations by Photography.
Year: 1895

page_text: Date of Application, 20th Nov., 1895
Complete Specification Left, 19th Aug., 1896-Accepted, 20th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements relating to the Preparation of Coloured Plates for
Obtaining Coloured Representations by Photography.
I, ALBERT BAUMGARTNER, Gentleman, of Thumringerstrasse 18 Lorrach, Baden,
in the Empire of Germany, do hereby declare the nature of this invention to be as
follows:-
It has been already proposed to carry out the process of three colour photographic
representation by combining the three colours on one plate, putting them in the form
of fine or delicate points or lines, forming in effect three coloured mosaic. On the plate
thus prepared, bromide of silver emulsion is put, exposed to light from behind the
plate, developed and a coloured representation thus obtained in one operation. This
process however has not been employed until now because the manufacturing of fine
grained, three coloured plates offers great difficulty in the usual method of chromo-
lithography.
The present process permits however of manufacturing such plates without particular
technical difficulty and allows at the same time of the employment of any number of
colours.
The essential feature of this method is that colours are put on alternately by
printing and in a chemical way in such a manner that by means of print and oil-colour
an incoherent coloured coating or graining is first given to the plate and then the
spots or places left uncoloured are afterwards dyed by means of dyeing, corroding or
etching (like the manipulation in cotton printing) in which operation the colour does
not adhere at the places previously printed with oil-colour.
When, for instance, a sheet of celluloid is coated with gelatine or a similar substance
and a red graining is printed from a granulated lithographic stone, or zinc plate in oil
colour, when this plate is dipped into the solution of an aniline colour, for instance
blue-green, only those spots will take up the colour which have not been printed with
the red oil-colour. When again a corn graining of yellow oil colour is printed on
which will partly fall over the red and partly over the blue, the result is orange and
green; finally the spots which are not covered by the yellow colour can be dyed still
farther as may be required.
It is obvious that in choosing the correct colours and repeating the described
process, several times, many colours can be put on. Also fixing of the colours under
the influence of light as in photographic pigment printing may be done. If for
instance on a sheet of celluloid a red and yellow graining are printed, so that the two
colours partly cover one another and the sheet is then coated with a layer of blue
gelatine which has been rendered sensible to light by means of bichromate of potash
when it is exposed to light from behind and developed as in the usual pigment process,
blue colour will be found on the spots which have remained free of oil colour, less will
remain on the yellow spots the result of which is green, on the red and orange spots
however no blue colour will remain by which means a similar effect will be produced
as in the example first given.
Dated this 20th day of November 1895.
HERBERT HADDAN & Co.,
Agents to the Applicant.

page_text: Improvements relating to the Preparation of Coloured Plates for
Obtaining Coloured Representations by Photography.
I, ALBERT BAUMGARTNER, of Thumringerstrasse 18, Lorrach, Baden, in the Empire
of Germany, Gentleman, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement:-
It has been already proposed to carry out the process of three colour photographic
reproduction by combining the three colours on one plate putting them in the form of
fine or delicate points or lines forming in effect three coloured mosaic. On the plate
thus prepared bromide of silver emulsion is put on, exposed to light from behind the
plate, developed and thus is obtained a coloured representation by one operation.
This process however has not been employed until now because the manufacturing
of fine grained three coloured plates offers great difficulty in the usual method of
chromolithography.
The present process permits however of manufacturing such plates without
particular technical difficulty and allows at the same time of the employment of any
number of colours.
The essential feature of this method is that colours are put on alternately by printing
and in a chemical way in such a way that by means of print and oil colour an
incoherent coloured coating graining is first given to the plate and then the spots or
places left uncoloured are afterwards coloured by means of dyeing, corroding, or
etching (like the manipulation in cotton printing) in which operation the colour does
not adhere at the places previously printed with oil colour.
If for instance a sheet of celluloid is coated with gelatine or a similar substance
and a red graining is printed on it from a granulated lithographic stone or zinc plate
in oil colour, when this plate is dipped into the solution of an aniline colour for
instance blue green, only those spots will take up the colour which have not been
printed with the red oil colour.
When again a graining of yellow oil colour is printed on which will partly fall over
the red and partly over the blue the result is orange and green; finally the spots
which are not covered by the yellow colour can be dyed still farther, as may be
required.
It is obvious that in choosing the correct colours and repeating the process several
times many colours can be put on. Also fixing of the colours under the influence of
light as in photographic pigment printing may be done. If for instance on a sheet of
celluloid a red and a yellow graining are printed so that the two colours partly cover
one another and the sheet is then coated with a layer of blue gelatine which has Leen
rendered sensitive to light by means of bichromate of potash when it is exposed to
light from behind and developed in the usual pigment process blue colour will be
found on the spots which have remained free of oil colour, less will remain on the
yellow spots, the result of which is green on the red and orange spots however no
blue colour will remain by which means a similar effect will be produced as in the
example first given.
One can also proceed in the following manner.
Upon a celluloid sheet is printed a red and yellow granulation so that the two
colours fall partly over each other then the sheet is coated with a layer of blue
gelatine which is made sensitive by means of bichromate of potash it is exposed from
behind and developed as in the usual pigment process. On the places which remained
white, blue will be fixed, on the yellows correspondingly less whereby green is
produced, on the red and orange coloured nothing at all, whereby a similar effect is
produced as in the first example.

page_text: Also here of course other colours and in other succession can be used.
If the layer is to be produced on glass one prints upon a transferring paper and the
colour is taken over to the glass.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed I declare that what I
clain is :-
The production of granulated variously coloured plates for photographic colour
representation in such a manner that the colours are transferred by printing and
dyeing alternately upon the surface so that the dyeing is only effected on the places
not yet covered by the mechanical printing.
Dated this 19th day of August 1806
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C.,
Agents for Applicant.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C.,
Agents for Applicant.